Merge Phacility/master into phorge

scripts/arcanist.php

@@ -68,7 +68,10 @@ $base_args->parsePartial(
     array(
       'name'    => 'conduit-uri',
       'param'   => 'uri',
-      'help'    => pht('Connect to Phabricator install specified by __uri__.'),
+      'help'    => pht(
+        'Connect to the %s (or compatible software) server specified by '.
+        '__uri__.',
+        PlatformSymbols::getPlatformServerName()),
     ),
     array(
       'name' => 'conduit-token',
@@ -85,7 +88,8 @@ $base_args->parsePartial(
       'repeat' => true,
       'help'   => pht(
         'Specify a runtime configuration value. This will take precedence '.
-        'over static values, and only affect the current arcanist invocation.'),
+        'over static values, and only affect the current process: the '.
+        'setting is not saved anywhere.'),
     ),
 ));
 
@@ -310,9 +314,13 @@ try {
       $message = phutil_console_format(
         "%s\n\n  - %s\n  - %s\n  - %s\n",
         pht(
-          'This command requires arc to connect to a Phabricator install, '.
+          'This command requires %s to connect to a %s (or compatible '.
-          'but no Phabricator installation is configured. To configure a '.
+          'software) server, but no %s server is configured. To configure a '.
-          'Phabricator URI:'),
+          '%s server URI:',
+          PlatformSymbols::getPlatformClientName(),
+          PlatformSymbols::getPlatformServerName(),
+          PlatformSymbols::getPlatformServerName(),
+          PlatformSymbols::getPlatformServerName()),
         pht(
           'set a default location with `%s`; or',
           'arc set-config default <uri>'),
@@ -688,10 +696,12 @@ function arcanist_load_libraries(
           "**<bg:yellow> %s </bg>** %s\n",
           pht('VERY META'),
           pht(
-            'You are running one copy of Arcanist (at path "%s") against '.
+            'You are running one copy of %s (at path "%s") against '.
-            'another copy of Arcanist (at path "%s"). Code in the current '.
+            'another copy of %s (at path "%s"). Code in the current '.
             'working directory will not be loaded or executed.',
+            PlatformSymbols::getPlatformClientName(),
             $executing_directory,
+            PlatformSymbols::getPlatformClientName(),
             $working_directory)));
     }
   }

src/__phutil_library_map__.php

@@ -188,6 +188,8 @@ phutil_register_library_map(array(
     'ArcanistDuplicateSwitchCaseXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistDuplicateSwitchCaseXHPASTLinterRuleTestCase.php',
     'ArcanistDynamicDefineXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistDynamicDefineXHPASTLinterRule.php',
     'ArcanistDynamicDefineXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistDynamicDefineXHPASTLinterRuleTestCase.php',
+    'ArcanistEachUseXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistEachUseXHPASTLinterRule.php',
+    'ArcanistEachUseXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistEachUseXHPASTLinterRuleTestCase.php',
     'ArcanistElseIfUsageXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistElseIfUsageXHPASTLinterRule.php',
     'ArcanistElseIfUsageXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistElseIfUsageXHPASTLinterRuleTestCase.php',
     'ArcanistEmptyFileXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistEmptyFileXHPASTLinterRule.php',
@@ -264,6 +266,8 @@ phutil_register_library_map(array(
     'ArcanistHgProxyClient' => 'hgdaemon/ArcanistHgProxyClient.php',
     'ArcanistHgProxyServer' => 'hgdaemon/ArcanistHgProxyServer.php',
     'ArcanistHgServerChannel' => 'hgdaemon/ArcanistHgServerChannel.php',
+    'ArcanistHostMemorySnapshot' => 'filesystem/memory/ArcanistHostMemorySnapshot.php',
+    'ArcanistHostMemorySnapshotTestCase' => 'filesystem/memory/__tests__/ArcanistHostMemorySnapshotTestCase.php',
     'ArcanistImplicitConstructorXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistImplicitConstructorXHPASTLinterRule.php',
     'ArcanistImplicitConstructorXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistImplicitConstructorXHPASTLinterRuleTestCase.php',
     'ArcanistImplicitFallthroughXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistImplicitFallthroughXHPASTLinterRule.php',
@@ -346,6 +350,7 @@ phutil_register_library_map(array(
     'ArcanistMercurialAPI' => 'repository/api/ArcanistMercurialAPI.php',
     'ArcanistMercurialCommitGraphQuery' => 'repository/graph/query/ArcanistMercurialCommitGraphQuery.php',
     'ArcanistMercurialCommitMessageHardpointQuery' => 'query/ArcanistMercurialCommitMessageHardpointQuery.php',
+    'ArcanistMercurialCommitSymbolCommitHardpointQuery' => 'ref/commit/ArcanistMercurialCommitSymbolCommitHardpointQuery.php',
     'ArcanistMercurialLandEngine' => 'land/engine/ArcanistMercurialLandEngine.php',
     'ArcanistMercurialLocalState' => 'repository/state/ArcanistMercurialLocalState.php',
     'ArcanistMercurialParser' => 'repository/parser/ArcanistMercurialParser.php',
@@ -419,6 +424,7 @@ phutil_register_library_map(array(
     'ArcanistPhutilXHPASTLinterStandard' => 'lint/linter/standards/phutil/ArcanistPhutilXHPASTLinterStandard.php',
     'ArcanistPlusOperatorOnStringsXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistPlusOperatorOnStringsXHPASTLinterRule.php',
     'ArcanistPlusOperatorOnStringsXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistPlusOperatorOnStringsXHPASTLinterRuleTestCase.php',
+    'ArcanistProductNameLiteralXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistProductNameLiteralXHPASTLinterRule.php',
     'ArcanistProjectConfigurationSource' => 'config/source/ArcanistProjectConfigurationSource.php',
     'ArcanistPrompt' => 'toolset/ArcanistPrompt.php',
     'ArcanistPromptResponse' => 'toolset/ArcanistPromptResponse.php',
@@ -632,6 +638,8 @@ phutil_register_library_map(array(
     'LinesOfALargeFile' => 'filesystem/linesofalarge/LinesOfALargeFile.php',
     'LinesOfALargeFileTestCase' => 'filesystem/linesofalarge/__tests__/LinesOfALargeFileTestCase.php',
     'MFilterTestHelper' => 'utils/__tests__/MFilterTestHelper.php',
+    'MethodCallFuture' => 'future/MethodCallFuture.php',
+    'MethodCallFutureTestCase' => 'future/__tests__/MethodCallFutureTestCase.php',
     'NoseTestEngine' => 'unit/engine/NoseTestEngine.php',
     'PHPASTParserTestCase' => 'parser/xhpast/__tests__/PHPASTParserTestCase.php',
     'PhageAction' => 'phage/action/PhageAction.php',
@@ -907,6 +915,7 @@ phutil_register_library_map(array(
     'PhutilVeryWowEnglishLocale' => 'internationalization/locales/PhutilVeryWowEnglishLocale.php',
     'PhutilWordPressFuture' => 'future/wordpress/PhutilWordPressFuture.php',
     'PhutilXHPASTBinary' => 'parser/xhpast/bin/PhutilXHPASTBinary.php',
+    'PlatformSymbols' => 'platform/PlatformSymbols.php',
     'PytestTestEngine' => 'unit/engine/PytestTestEngine.php',
     'TempFile' => 'filesystem/TempFile.php',
     'TestAbstractDirectedGraph' => 'utils/__tests__/TestAbstractDirectedGraph.php',
@@ -959,6 +968,7 @@ phutil_register_library_map(array(
     'nonempty' => 'utils/utils.php',
     'phlog' => 'error/phlog.php',
     'pht' => 'internationalization/pht.php',
+    'pht_list' => 'internationalization/pht.php',
     'phutil_build_http_querystring' => 'utils/utils.php',
     'phutil_build_http_querystring_from_pairs' => 'utils/utils.php',
     'phutil_censor_credentials' => 'utils/utils.php',
@@ -972,7 +982,6 @@ phutil_register_library_map(array(
     'phutil_count' => 'internationalization/pht.php',
     'phutil_date_format' => 'utils/viewutils.php',
     'phutil_decode_mime_header' => 'utils/utils.php',
-    'phutil_deprecated' => 'init/lib/moduleutils.php',
     'phutil_describe_type' => 'utils/utils.php',
     'phutil_encode_log' => 'utils/utils.php',
     'phutil_error_listener_example' => 'error/phlog.php',
@@ -1008,6 +1017,9 @@ phutil_register_library_map(array(
     'phutil_load_library' => 'init/lib/moduleutils.php',
     'phutil_loggable_string' => 'utils/utils.php',
     'phutil_microseconds_since' => 'utils/utils.php',
+    'phutil_nonempty_scalar' => 'utils/utils.php',
+    'phutil_nonempty_string' => 'utils/utils.php',
+    'phutil_nonempty_stringlike' => 'utils/utils.php',
     'phutil_parse_bytes' => 'utils/viewutils.php',
     'phutil_partition' => 'utils/utils.php',
     'phutil_passthru' => 'future/exec/execx.php',
@@ -1245,6 +1257,8 @@ phutil_register_library_map(array(
     'ArcanistDuplicateSwitchCaseXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistDynamicDefineXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistDynamicDefineXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
+    'ArcanistEachUseXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
+    'ArcanistEachUseXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistElseIfUsageXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistElseIfUsageXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistEmptyFileXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
@@ -1321,6 +1335,8 @@ phutil_register_library_map(array(
     'ArcanistHgProxyClient' => 'Phobject',
     'ArcanistHgProxyServer' => 'Phobject',
     'ArcanistHgServerChannel' => 'PhutilProtocolChannel',
+    'ArcanistHostMemorySnapshot' => 'Phobject',
+    'ArcanistHostMemorySnapshotTestCase' => 'PhutilTestCase',
     'ArcanistImplicitConstructorXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistImplicitConstructorXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistImplicitFallthroughXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
@@ -1403,6 +1419,7 @@ phutil_register_library_map(array(
     'ArcanistMercurialAPI' => 'ArcanistRepositoryAPI',
     'ArcanistMercurialCommitGraphQuery' => 'ArcanistCommitGraphQuery',
     'ArcanistMercurialCommitMessageHardpointQuery' => 'ArcanistWorkflowMercurialHardpointQuery',
+    'ArcanistMercurialCommitSymbolCommitHardpointQuery' => 'ArcanistWorkflowMercurialHardpointQuery',
     'ArcanistMercurialLandEngine' => 'ArcanistLandEngine',
     'ArcanistMercurialLocalState' => 'ArcanistRepositoryLocalState',
     'ArcanistMercurialParser' => 'Phobject',
@@ -1476,6 +1493,7 @@ phutil_register_library_map(array(
     'ArcanistPhutilXHPASTLinterStandard' => 'ArcanistLinterStandard',
     'ArcanistPlusOperatorOnStringsXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistPlusOperatorOnStringsXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
+    'ArcanistProductNameLiteralXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistProjectConfigurationSource' => 'ArcanistWorkingCopyConfigurationSource',
     'ArcanistPrompt' => 'Phobject',
     'ArcanistPromptResponse' => 'Phobject',
@@ -1696,6 +1714,8 @@ phutil_register_library_map(array(
     'LinesOfALargeFile' => 'LinesOfALarge',
     'LinesOfALargeFileTestCase' => 'PhutilTestCase',
     'MFilterTestHelper' => 'Phobject',
+    'MethodCallFuture' => 'Future',
+    'MethodCallFutureTestCase' => 'PhutilTestCase',
     'NoseTestEngine' => 'ArcanistUnitTestEngine',
     'PHPASTParserTestCase' => 'PhutilTestCase',
     'PhageAction' => 'Phobject',
@@ -1991,6 +2011,7 @@ phutil_register_library_map(array(
     'PhutilVeryWowEnglishLocale' => 'PhutilLocale',
     'PhutilWordPressFuture' => 'FutureProxy',
     'PhutilXHPASTBinary' => 'Phobject',
+    'PlatformSymbols' => 'Phobject',
     'PytestTestEngine' => 'ArcanistUnitTestEngine',
     'TempFile' => 'Phobject',
     'TestAbstractDirectedGraph' => 'AbstractDirectedGraph',

src/__tests__/PhutilLibraryTestCase.php

@@ -125,8 +125,8 @@ class PhutilLibraryTestCase extends PhutilTestCase {
               $failures[] = pht(
                 'Class "%s" implements method "%s" with the wrong visibility. '.
                 'The method has visibility "%s", but it is defined in parent '.
-                '"%s" with visibility "%s". In Phabricator, a method which '.
+                '"%s" with visibility "%s". A method which overrides another '.
-                'overrides another must always have the same visibility.',
+                'must always have the same visibility.',
                 $class_name,
                 $method_name,
                 $this->getVisibility($method),

src/conduit/ArcanistConduitEngine.php

@@ -89,8 +89,8 @@ final class ArcanistConduitEngine
     $block = id(new PhutilConsoleBlock())
       ->addParagraph(
         pht(
-          'This command needs to communicate with Phabricator, but no '.
+          'This command needs to communicate with a server, but no '.
-          'Phabricator URI is configured.'))
+          'server URI is configured.'))
       ->addList($list);
 
     throw new ArcanistUsageException($block->drawConsoleString());

src/config/arc/ArcanistArcConfigurationEngineExtension.php

@@ -71,10 +71,10 @@ final class ArcanistArcConfigurationEngineExtension
         ->setSummary(pht('Repository for the current working copy.'))
         ->setHelp(
           pht(
-            'Associate the working copy with a specific Phabricator '.
+            'Associate the working copy with a specific repository. Normally, '.
-            'repository. Normally, Arcanist can figure this association '.
+            'this association can be determined automatically, but if your '.
-            'out on its own, but if your setup is unusual you can use '.
+            'setup is unusual you can use this option to tell it what the '.
-            'this option to tell it what the desired value is.'))
+            'desired value is.'))
         ->setExamples(
           array(
             'libexample',
@@ -89,14 +89,15 @@ final class ArcanistArcConfigurationEngineExtension
             'conduit_uri',
             'default',
           ))
-        ->setSummary(pht('Phabricator install to connect to.'))
+        ->setSummary(pht('Server to connect to.'))
         ->setHelp(
           pht(
             'Associates this working copy with a specific installation of '.
-            'Phabricator.'))
+            '%s (or compatible software).',
+            PlatformSymbols::getPlatformServerName()))
         ->setExamples(
           array(
-            'https://phabricator.mycompany.com/',
+            'https://devtools.example.com/',
           )),
       id(new ArcanistAliasesConfigOption())
         ->setKey(self::KEY_ALIASES)

src/configuration/ArcanistBlindlyTrustHTTPEngineExtension.php

@@ -15,7 +15,7 @@ final class ArcanistBlindlyTrustHTTPEngineExtension
   }
 
   public function getExtensionName() {
-    return pht('Arcanist HTTPS Trusted Domains');
+    return pht('HTTPS Trusted Domains');
   }
 
   public function shouldTrustAnySSLAuthorityForURI(PhutilURI $uri) {

src/configuration/ArcanistConfigurationManager.php

@@ -258,7 +258,7 @@ final class ArcanistConfigurationManager extends Phobject {
   }
 
   public function getUserConfigurationFileLocation() {
-    if (strlen($this->customArcrcFilename)) {
+    if ($this->customArcrcFilename !== null) {
       return $this->customArcrcFilename;
     }
 

src/configuration/ArcanistSettings.php

@@ -7,11 +7,11 @@ final class ArcanistSettings extends Phobject {
       'default' => array(
         'type' => 'string',
         'help' => pht(
-          'The URI of a Phabricator install to connect to by default, if '.
+          'The URI of a server to connect to by default, if '.
-          '%s is run in a project without a Phabricator URI or run outside '.
+          '%s is run in a project without a configured URI or run outside '.
           'of a project.',
           'arc'),
-        'example' => '"http://phabricator.example.com/"',
+        'example' => '"http://devtools.example.com/"',
       ),
       'base' => array(
         'type' => 'string',
@@ -35,7 +35,7 @@ final class ArcanistSettings extends Phobject {
         'type' => 'string',
         'example' => '"X"',
         'help' => pht(
-          'Associate the working copy with a specific Phabricator repository. '.
+          'Associate the working copy with a specific repository. '.
           'Normally, %s can figure this association out on its own, but if '.
           'your setup is unusual you can use this option to tell it what the '.
           'desired value is.',
@@ -44,10 +44,9 @@ final class ArcanistSettings extends Phobject {
       'phabricator.uri' => array(
         'type' => 'string',
         'legacy' => 'conduit_uri',
-        'example' => '"https://phabricator.mycompany.com/"',
+        'example' => '"https://devtools.example.com/"',
         'help' => pht(
-          'Associates this working copy with a specific installation of '.
+          'Associates this working copy with a specific server.'),
-          'Phabricator.'),
       ),
       'lint.engine' => array(
         'type' => 'string',
@@ -96,8 +95,8 @@ final class ArcanistSettings extends Phobject {
       'https.cabundle' => array(
         'type' => 'string',
         'help' => pht(
-          "Path to a custom CA bundle file to be used for arcanist's cURL ".
+          "Path to a custom CA bundle file to be used for cURL calls. ".
-          "calls. This is used primarily when your conduit endpoint is ".
+          "This is used primarily when your conduit endpoint is ".
           "behind HTTPS signed by your organization's internal CA."),
         'example' => 'support/yourca.pem',
       ),
@@ -118,7 +117,7 @@ final class ArcanistSettings extends Phobject {
           'Whether %s should permit the automatic stashing of changes in the '.
           'working directory when requiring a clean working copy. This option '.
           'should only be used when users understand how to restore their '.
-          'working directory from the local stash if an Arcanist operation '.
+          'working directory from the local stash if an operation '.
           'causes an unrecoverable error.',
           'arc'),
         'default' => false,

src/console/PhutilConsoleFormatter.php

@@ -22,23 +22,38 @@ final class PhutilConsoleFormatter extends Phobject {
 
   public static function getDisableANSI() {
     if (self::$disableANSI === null) {
+      self::$disableANSI = self::newShouldDisableAnsi();
+    }
+    return self::$disableANSI;
+  }
+
+  private static function newShouldDisableANSI() {
     $term = phutil_utf8_strtolower(getenv('TERM'));
+
     // ansicon enables ANSI support on Windows
     if (!$term && getenv('ANSICON')) {
       $term = 'ansi';
     }
 
-      if (phutil_is_windows() && $term !== 'cygwin' && $term !== 'ansi') {
+
-        self::$disableANSI = true;
+    if (phutil_is_windows()) {
-      } else if (!defined('STDOUT')) {
+      if ($term !== 'cygwin' && $term !== 'ansi') {
-        self::$disableANSI = true;
+        return true;
-      } else if (function_exists('posix_isatty') && !posix_isatty(STDOUT)) {
-        self::$disableANSI = true;
-      } else {
-        self::$disableANSI = false;
       }
     }
-    return self::$disableANSI;
+
+    $stdout = PhutilSystem::getStdoutHandle();
+    if ($stdout === null) {
+      return true;
+    }
+
+    if (function_exists('posix_isatty')) {
+      if (!posix_isatty($stdout)) {
+        return true;
+      }
+    }
+
+    return false;
   }
 
   public static function formatString($format /* ... */) {

src/console/PhutilInteractiveEditor.php

@@ -22,6 +22,7 @@ final class PhutilInteractiveEditor extends Phobject {
   private $offset   = 0;
   private $preferred;
   private $fallback;
+  private $taskMessage;
 
 
 /* -(  Creating a New Editor  )---------------------------------------------- */
@@ -74,6 +75,20 @@ final class PhutilInteractiveEditor extends Phobject {
     $editor = $this->getEditor();
     $offset = $this->getLineOffset();
 
+    $binary = basename($editor);
+
+    // This message is primarily an assistance to users with GUI-based
+    // editors configured. Users with terminal-based editors won't have a
+    // chance to see this prior to the editor being launched.
+    echo tsprintf(
+      "%s\n",
+      pht('Launching editor "%s"...', $binary));
+
+    $task_message = $this->getTaskMessage();
+    if ($task_message !== null) {
+      echo tsprintf("%s\n", $task_message);
+    }
+
     $err = $this->invokeEditor($editor, $path, $offset);
 
     if ($err) {
@@ -85,7 +100,6 @@ final class PhutilInteractiveEditor extends Phobject {
         'vim' => true,
       );
 
-      $binary = basename($editor);
       if (isset($vi_binaries[$binary])) {
         // This runs "Q" (an invalid command), then "q" (a valid command,
         // meaning "quit"). Vim binaries with behavior that makes them poor
@@ -266,6 +280,33 @@ final class PhutilInteractiveEditor extends Phobject {
     return $this;
   }
 
+  /**
+   * Set the message that identifies the task for which the editor is being
+   * launched, displayed to the user prior to it being launched.
+   *
+   * @param  string  The message to display to the user.
+   * @return $this
+   *
+   * @task config
+   */
+  public function setTaskMessage($task_message) {
+    $this->taskMessage = $task_message;
+    return $this;
+  }
+
+  /**
+   * Retrieve the current message that will display to the user just prior to
+   * invoking the editor.
+   *
+   * @return string  The message that will display to the user, or null if no
+   *   message will be displayed.
+   *
+   * @task config
+   */
+  public function getTaskMessage() {
+    return $this->taskMessage;
+  }
+
 
   /**
    * Get the name of the editor program to use. The value of the environmental

src/differential/ArcanistDifferentialCommitMessage.php

@@ -139,10 +139,10 @@ final class ArcanistDifferentialCommitMessage extends Phobject {
     throw new ArcanistUsageException(
       pht(
         'Invalid "Differential Revision" field in commit message. This field '.
-        'should have a revision identifier like "%s" or a Phabricator URI '.
+        'should have a revision identifier like "%s" or a server URI '.
         'like "%s", but has "%s".',
         'D123',
-        'https://phabricator.example.com/D123',
+        'https://devtools.example.com/D123',
         $revision_value));
   }
 

src/error/PhutilErrorHandler.php

@@ -181,7 +181,6 @@ final class PhutilErrorHandler extends Phobject {
    * @task internal
    */
   public static function handleError($num, $str, $file, $line, $ctx = null) {
-
     foreach (self::$traps as $trap) {
       $trap->addError($num, $str, $file, $line);
     }
@@ -378,7 +377,7 @@ final class PhutilErrorHandler extends Phobject {
    * @task internal
    */
   public static function dispatchErrorMessage($event, $value, $metadata) {
-    $timestamp = strftime('%Y-%m-%d %H:%M:%S');
+    $timestamp = date('Y-m-d H:i:s');
 
     switch ($event) {
       case self::ERROR:
@@ -425,16 +424,6 @@ final class PhutilErrorHandler extends Phobject {
           $metadata['file'],
           $metadata['line']);
 
-        $metadata['default_message'] = $default_message;
-        error_log($default_message);
-        break;
-      case self::DEPRECATED:
-        $default_message = sprintf(
-          '[%s] DEPRECATED: %s is deprecated; %s',
-          $timestamp,
-          $value,
-          $metadata['why']);
-
         $metadata['default_message'] = $default_message;
         error_log($default_message);
         break;

src/filesystem/PhutilDirectoryFixture.php

@@ -28,6 +28,8 @@ final class PhutilDirectoryFixture extends Phobject {
   }
 
   public function getPath($to_file = null) {
+    $to_file = phutil_string_cast($to_file);
+
     return $this->path.'/'.ltrim($to_file, '/');
   }
 

src/filesystem/PhutilErrorLog.php

@@ -94,7 +94,7 @@ final class PhutilErrorLog
 
     if (strlen($message)) {
       $message = tsprintf("%B\n", $message);
-      @fwrite(STDERR, $message);
+      PhutilSystem::writeStderr($message);
     }
   }
 

src/filesystem/binary/PhutilMercurialBinaryAnalyzer.php

@@ -7,6 +7,8 @@ final class PhutilMercurialBinaryAnalyzer
 
   const CAPABILITY_FILES = 'files';
   const CAPABILITY_INJECTION = 'injection';
+  const CAPABILITY_TEMPLATE_PNODE = 'template_pnode';
+  const CAPABILTIY_ANNOTATE_TEMPLATES = 'annotate_templates';
 
   protected function newBinaryVersion() {
     $future = id(new ExecFuture('hg --version --quiet'))
@@ -60,6 +62,33 @@ final class PhutilMercurialBinaryAnalyzer
       self::CAPABILITY_INJECTION);
   }
 
+  /**
+   * When using `--template` the format for accessing individual parents
+   * changed from `{p1node}` to `{p1.node}` in Mercurial 4.9.
+   *
+   * @return boolean  True if the version of Mercurial is new enough to support
+   *   the `{p1.node}` format in templates, or false if otherwise.
+   */
+  public function isMercurialTemplatePnodeAvailable() {
+    return self::versionHasCapability(
+      $this->requireBinaryVersion(),
+      self::CAPABILITY_TEMPLATE_PNODE);
+  }
+
+  /**
+   * The `hg annotate` command did not accept the `--template` argument until
+   * version 4.6. It appears to function in version 4.5 however it's not
+   * documented and wasn't announced until the 4.6 release.
+   *
+   * @return boolean  True if the version of Mercurial is new enough to support
+   *   the `--template` option when using `hg annotate`, or false if otherwise.
+   */
+  public function isMercurialAnnotateTemplatesAvailable() {
+    return self::versionHasCapability(
+      $this->requireBinaryVersion(),
+      self::CAPABILTIY_ANNOTATE_TEMPLATES);
+  }
+
 
   public static function versionHasCapability(
     $mercurial_version,
@@ -70,6 +99,10 @@ final class PhutilMercurialBinaryAnalyzer
         return version_compare($mercurial_version, '3.2', '>=');
       case self::CAPABILITY_INJECTION:
         return version_compare($mercurial_version, '3.2.4', '<');
+      case self::CAPABILITY_TEMPLATE_PNODE:
+        return version_compare($mercurial_version, '4.9', '>=');
+      case self::CAPABILTIY_ANNOTATE_TEMPLATES:
+        return version_compare($mercurial_version, '4.6', '>=');
       default:
         throw new Exception(
           pht(

src/filesystem/linesofalarge/LinesOfALarge.php

@@ -212,7 +212,7 @@ abstract class LinesOfALarge extends Phobject implements Iterator {
         if (strlen($this->buf)) {
           $this->num++;
           $this->line = $this->buf;
-          $this->buf = null;
+          $this->buf = '';
         } else {
           $this->valid = false;
         }

src/filesystem/memory/ArcanistHostMemorySnapshot.php

@@ -0,0 +1,156 @@
+<?php
+
+final class ArcanistHostMemorySnapshot
+  extends Phobject {
+
+  private $memorySnapshot;
+
+  public static function newFromRawMeminfo($meminfo_source, $meminfo_raw) {
+    $snapshot = new self();
+
+    $snapshot->memorySnapshot = $snapshot->readMeminfoSnapshot(
+      $meminfo_source,
+      $meminfo_raw);
+
+    return $snapshot;
+  }
+
+  public function getTotalSwapBytes() {
+    $info = $this->getMemorySnapshot();
+    return $info['swap.total'];
+  }
+
+  private function getMemorySnapshot() {
+    if ($this->memorySnapshot === null) {
+      $this->memorySnapshot = $this->newMemorySnapshot();
+    }
+
+    return $this->memorySnapshot;
+  }
+
+  private function newMemorySnapshot() {
+    $meminfo_source = '/proc/meminfo';
+    list($meminfo_raw) = execx('cat %s', $meminfo_source);
+    return $this->readMeminfoSnapshot($meminfo_source, $meminfo_raw);
+  }
+
+  private function readMeminfoSnapshot($meminfo_source, $meminfo_raw) {
+    $meminfo_pattern = '/^([^:]+):\s+(\S+)(?:\s+(kB))?\z/';
+
+    $meminfo_map = array();
+
+    $meminfo_lines = phutil_split_lines($meminfo_raw, false);
+    foreach ($meminfo_lines as $meminfo_line) {
+      $meminfo_parts = phutil_preg_match($meminfo_pattern, $meminfo_line);
+
+      if (!$meminfo_parts) {
+        throw new Exception(
+          pht(
+            'Unable to parse line in meminfo source "%s": "%s".',
+            $meminfo_source,
+            $meminfo_line));
+      }
+
+      $meminfo_key = $meminfo_parts[1];
+      $meminfo_value = $meminfo_parts[2];
+      $meminfo_unit = idx($meminfo_parts, 3);
+
+      if (isset($meminfo_map[$meminfo_key])) {
+        throw new Exception(
+          pht(
+            'Encountered duplicate meminfo key "%s" in meminfo source "%s".',
+            $meminfo_key,
+            $meminfo_source));
+      }
+
+      $meminfo_map[$meminfo_key] = array(
+        'value' => $meminfo_value,
+        'unit' => $meminfo_unit,
+      );
+    }
+
+    $swap_total_bytes = $this->readMeminfoBytes(
+      $meminfo_source,
+      $meminfo_map,
+      'SwapTotal');
+
+    return array(
+      'swap.total' => $swap_total_bytes,
+    );
+  }
+
+  private function readMeminfoBytes(
+    $meminfo_source,
+    $meminfo_map,
+    $meminfo_key) {
+
+    $meminfo_integer = $this->readMeminfoIntegerValue(
+      $meminfo_source,
+      $meminfo_map,
+      $meminfo_key);
+
+    $meminfo_unit = $meminfo_map[$meminfo_key]['unit'];
+    if ($meminfo_unit === null) {
+      throw new Exception(
+        pht(
+          'Expected to find a byte unit for meminfo key "%s" in meminfo '.
+          'source "%s", found no unit.',
+          $meminfo_key,
+          $meminfo_source));
+    }
+
+    if ($meminfo_unit !== 'kB') {
+      throw new Exception(
+        pht(
+          'Expected unit for meminfo key "%s" in meminfo source "%s" '.
+          'to be "kB", found "%s".',
+          $meminfo_key,
+          $meminfo_source,
+          $meminfo_unit));
+    }
+
+    $meminfo_bytes = ($meminfo_integer * 1024);
+
+    return $meminfo_bytes;
+  }
+
+  private function readMeminfoIntegerValue(
+    $meminfo_source,
+    $meminfo_map,
+    $meminfo_key) {
+
+    $meminfo_value = $this->readMeminfoValue(
+      $meminfo_source,
+      $meminfo_map,
+      $meminfo_key);
+
+    if (!phutil_preg_match('/^\d+\z/', $meminfo_value)) {
+      throw new Exception(
+        pht(
+          'Expected to find an integer value for meminfo key "%s" in '.
+          'meminfo source "%s", found "%s".',
+          $meminfo_key,
+          $meminfo_source,
+          $meminfo_value));
+    }
+
+    return (int)$meminfo_value;
+  }
+
+  private function readMeminfoValue(
+    $meminfo_source,
+    $meminfo_map,
+    $meminfo_key) {
+
+    if (!isset($meminfo_map[$meminfo_key])) {
+      throw new Exception(
+        pht(
+          'Expected to find meminfo key "%s" in meminfo source "%s".',
+          $meminfo_key,
+          $meminfo_source));
+    }
+
+    return $meminfo_map[$meminfo_key]['value'];
+  }
+
+}

src/filesystem/memory/__tests__/ArcanistHostMemorySnapshotTestCase.php

@@ -0,0 +1,51 @@
+<?php
+
+final class ArcanistHostMemorySnapshotTestCase
+  extends PhutilTestCase {
+
+  public function testSnapshotSwapTotalBytes() {
+    $test_cases = array(
+      'meminfo_swap_normal.txt' => 4294963200,
+      'meminfo_swap_zero.txt' => 0,
+      'meminfo_swap_missing.txt' => false,
+      'meminfo_swap_invalid.txt' => false,
+      'meminfo_swap_badunits.txt' => false,
+      'meminfo_swap_duplicate.txt' => false,
+    );
+
+    $test_dir = dirname(__FILE__).'/data/';
+
+    foreach ($test_cases as $test_file => $expect) {
+      $test_data = Filesystem::readFile($test_dir.$test_file);
+
+      $caught = null;
+      $actual = null;
+      try {
+        $snapshot = ArcanistHostMemorySnapshot::newFromRawMeminfo(
+          $test_file,
+          $test_data);
+        $actual = $snapshot->getTotalSwapBytes();
+      } catch (Exception $ex) {
+        if ($expect === false) {
+          $caught = $ex;
+        } else {
+          throw $ex;
+        }
+      } catch (Throwable $ex) {
+        throw $ex;
+      }
+
+      if ($expect === false) {
+        $this->assertTrue(
+          ($caught instanceof Exception),
+          pht('Expected exception for "%s".', $test_file));
+      } else {
+        $this->assertEqual(
+          $expect,
+          $actual,
+          pht('Result for "%s".', $test_file));
+      }
+    }
+  }
+
+}

src/filesystem/memory/__tests__/data/meminfo_swap_badunits.txt

@@ -0,0 +1,2 @@
+MemTotal:        8140924 kB
+SwapTotal:       4194 mB

src/filesystem/memory/__tests__/data/meminfo_swap_duplicate.txt

@@ -0,0 +1,3 @@
+MemTotal:        8140924 kB
+SwapTotal:       4194300 kB
+SwapTotal:       4194300 kB

src/filesystem/memory/__tests__/data/meminfo_swap_invalid.txt

@@ -0,0 +1,2 @@
+MemTotal:        8140924 kB
+SwapTotal:       aardvark kB

src/filesystem/memory/__tests__/data/meminfo_swap_missing.txt

@@ -0,0 +1 @@
+MemTotal:        8140924 kB

src/filesystem/memory/__tests__/data/meminfo_swap_normal.txt

@@ -0,0 +1,51 @@
+MemTotal:        8140924 kB
+MemFree:         1760456 kB
+MemAvailable:    4264888 kB
+Buffers:           36784 kB
+Cached:          2654788 kB
+SwapCached:         2132 kB
+Active:           331128 kB
+Inactive:        5677400 kB
+Active(anon):      22692 kB
+Inactive(anon):  3325560 kB
+Active(file):     308436 kB
+Inactive(file):  2351840 kB
+Unevictable:       23012 kB
+Mlocked:           18476 kB
+SwapTotal:       4194300 kB
+SwapFree:        2440444 kB
+Dirty:                44 kB
+Writeback:             0 kB
+AnonPages:       3337944 kB
+Mapped:           117424 kB
+Shmem:             19872 kB
+KReclaimable:     124728 kB
+Slab:             240640 kB
+SReclaimable:     124728 kB
+SUnreclaim:       115912 kB
+KernelStack:        6736 kB
+PageTables:        42044 kB
+NFS_Unstable:          0 kB
+Bounce:                0 kB
+WritebackTmp:          0 kB
+CommitLimit:     8264760 kB
+Committed_AS:    6994880 kB
+VmallocTotal:   34359738367 kB
+VmallocUsed:       16656 kB
+VmallocChunk:          0 kB
+Percpu:             9856 kB
+HardwareCorrupted:     0 kB
+AnonHugePages:         0 kB
+ShmemHugePages:        0 kB
+ShmemPmdMapped:        0 kB
+FileHugePages:         0 kB
+FilePmdMapped:         0 kB
+HugePages_Total:       0
+HugePages_Free:        0
+HugePages_Rsvd:        0
+HugePages_Surp:        0
+Hugepagesize:       2048 kB
+Hugetlb:               0 kB
+DirectMap4k:      270336 kB
+DirectMap2M:     8118272 kB
+DirectMap1G:     1048576 kB

src/filesystem/memory/__tests__/data/meminfo_swap_zero.txt

@@ -0,0 +1,51 @@
+MemTotal:        8140924 kB
+MemFree:         1760456 kB
+MemAvailable:    4264888 kB
+Buffers:           36784 kB
+Cached:          2654788 kB
+SwapCached:         2132 kB
+Active:           331128 kB
+Inactive:        5677400 kB
+Active(anon):      22692 kB
+Inactive(anon):  3325560 kB
+Active(file):     308436 kB
+Inactive(file):  2351840 kB
+Unevictable:       23012 kB
+Mlocked:           18476 kB
+SwapTotal:       0 kB
+SwapFree:        2440444 kB
+Dirty:                44 kB
+Writeback:             0 kB
+AnonPages:       3337944 kB
+Mapped:           117424 kB
+Shmem:             19872 kB
+KReclaimable:     124728 kB
+Slab:             240640 kB
+SReclaimable:     124728 kB
+SUnreclaim:       115912 kB
+KernelStack:        6736 kB
+PageTables:        42044 kB
+NFS_Unstable:          0 kB
+Bounce:                0 kB
+WritebackTmp:          0 kB
+CommitLimit:     8264760 kB
+Committed_AS:    6994880 kB
+VmallocTotal:   34359738367 kB
+VmallocUsed:       16656 kB
+VmallocChunk:          0 kB
+Percpu:             9856 kB
+HardwareCorrupted:     0 kB
+AnonHugePages:         0 kB
+ShmemHugePages:        0 kB
+ShmemPmdMapped:        0 kB
+FileHugePages:         0 kB
+FilePmdMapped:         0 kB
+HugePages_Total:       0
+HugePages_Free:        0
+HugePages_Rsvd:        0
+HugePages_Surp:        0
+Hugepagesize:       2048 kB
+Hugetlb:               0 kB
+DirectMap4k:      270336 kB
+DirectMap2M:     8118272 kB
+DirectMap1G:     1048576 kB

src/future/MethodCallFuture.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * Degenerate future which resolves by calling a method.
+ *
+ *   $future = new MethodCallFuture($calculator, 'add', 1, 2);
+ *
+ * This future is similar to @{class:ImmediateFuture}, but may make it easier
+ * to implement exception behavior correctly. See T13666.
+ */
+final class MethodCallFuture extends Future {
+
+  private $callObject;
+  private $callMethod;
+  private $callArgv;
+
+  public function __construct($object, $method /* , ...*/ ) {
+    $argv = func_get_args();
+
+    $this->callObject = $object;
+    $this->callMethod = $method;
+    $this->callArgv = array_slice($argv, 2);
+  }
+
+  public function isReady() {
+
+    $call = array($this->callObject, $this->callMethod);
+    $argv = $this->callArgv;
+
+    $result = call_user_func_array($call, $argv);
+    $this->setResult($result);
+
+    return true;
+  }
+
+}

src/future/__tests__/MethodCallFutureTestCase.php

@@ -0,0 +1,57 @@
+<?php
+
+final class MethodCallFutureTestCase extends PhutilTestCase {
+
+  public function testMethodCallFutureSums() {
+    $future = new MethodCallFuture($this, 'getSum', 1, 2, 3);
+    $result = $future->resolve();
+
+    $this->assertEqual(6, $result, pht('MethodCallFuture: getSum(1, 2, 3)'));
+
+    $future = new MethodCallFuture($this, 'getSum');
+    $result = $future->resolve();
+
+    $this->assertEqual(0, $result, pht('MethodCallFuture: getSum()'));
+  }
+
+  public function testMethodCallFutureExceptions() {
+    $future = new MethodCallFuture($this, 'raiseException');
+
+    // See T13666. Using "FutureIterator" to advance the future until it is
+    // ready to resolve should NOT throw an exception.
+
+    foreach (new FutureIterator(array($future)) as $resolvable) {
+      // Continue below...
+    }
+
+    $caught = null;
+    try {
+      $future->resolve();
+    } catch (PhutilMethodNotImplementedException $ex) {
+      $caught = $ex;
+    }
+
+    $this->assertTrue(
+      ($caught instanceof PhutilMethodNotImplementedException),
+      pht('MethodCallFuture: exceptions raise at resolution.'));
+  }
+
+  public function getSum(/* ... */) {
+    $args = func_get_args();
+
+    $sum = 0;
+    foreach ($args as $arg) {
+      $sum += $arg;
+    }
+
+    return $sum;
+  }
+
+  public function raiseException() {
+    // We just want to throw any narrow exception so the test isn't catching
+    // too broad an exception type. This is simulating some exception during
+    // future resolution.
+    throw new PhutilMethodNotImplementedException();
+  }
+
+}

src/future/aws/PhutilAWSException.php

@@ -49,4 +49,24 @@ final class PhutilAWSException extends Exception {
     return $this->httpStatus;
   }
 
+  public function isNotFoundError() {
+    if ($this->hasErrorCode('InvalidVolume.NotFound')) {
+      return true;
+    }
+
+    return false;
+  }
+
+  private function hasErrorCode($code) {
+    $errors = idx($this->params, 'Errors', array());
+
+    foreach ($errors as $error) {
+      if ($error[0] === $code) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
 }

src/future/aws/PhutilAWSFuture.php

@@ -142,6 +142,7 @@ abstract class PhutilAWSFuture extends FutureProxy {
     try {
       $xml = @(new SimpleXMLElement($body));
     } catch (Exception $ex) {
+      phlog($ex);
       $xml = null;
     }
 
@@ -155,9 +156,28 @@ abstract class PhutilAWSFuture extends FutureProxy {
       );
       if ($xml) {
         $params['RequestID'] = $xml->RequestID[0];
-        $errors = array($xml->Error);
+
-        foreach ($errors as $error) {
+        // NOTE: The S3 and EC2 APIs return slightly different error responses.
-          $params['Errors'][] = array($error->Code, $error->Message);
+
+        // In S3 responses, there's a simple top-level "<Error>" element.
+        $s3_error = $xml->Error;
+        if ($s3_error) {
+          $params['Errors'][] = array(
+            phutil_string_cast($s3_error->Code),
+            phutil_string_cast($s3_error->Message),
+          );
+        }
+
+        // In EC2 responses, there's an "<Errors>" element with "<Error>"
+        // children.
+        $ec2_errors = $xml->Errors[0];
+        if ($ec2_errors) {
+          foreach ($ec2_errors as $error) {
+            $params['Errors'][] = array(
+              phutil_string_cast($error->Code),
+              phutil_string_cast($error->Message),
+            );
+          }
         }
       }
 

src/future/exec/ExecFuture.php

@@ -192,14 +192,21 @@ final class ExecFuture extends PhutilExecutableFuture {
    * @task interact
    */
   public function read() {
-    $stdout = $this->readStdout();
+    $stdout_value = $this->readStdout();
+
+    $stderr = $this->stderr;
+    if ($stderr === null) {
+      $stderr_value = '';
+    } else {
+      $stderr_value = substr($stderr, $this->stderrPos);
+    }
 
     $result = array(
-      $stdout,
+      $stdout_value,
-      (string)substr($this->stderr, $this->stderrPos),
+      $stderr_value,
     );
 
-    $this->stderrPos = strlen($this->stderr);
+    $this->stderrPos = $this->getStderrBufferLength();
 
     return $result;
   }
@@ -209,8 +216,16 @@ final class ExecFuture extends PhutilExecutableFuture {
       $this->updateFuture(); // Sync
     }
 
-    $result = (string)substr($this->stdout, $this->stdoutPos);
+    $stdout = $this->stdout;
-    $this->stdoutPos = strlen($this->stdout);
+
+    if ($stdout === null) {
+      $result = '';
+    } else {
+      $result = substr($stdout, $this->stdoutPos);
+    }
+
+    $this->stdoutPos = $this->getStdoutBufferLength();
+
     return $result;
   }
 
@@ -475,7 +490,7 @@ final class ExecFuture extends PhutilExecutableFuture {
    * @task internal
    */
   public function isReadBufferEmpty() {
-    return !strlen($this->stdout);
+    return !$this->getStdoutBufferLength();
   }
 
 
@@ -757,14 +772,17 @@ final class ExecFuture extends PhutilExecutableFuture {
     $max_stdout_read_bytes = PHP_INT_MAX;
     $max_stderr_read_bytes = PHP_INT_MAX;
     if ($read_buffer_size !== null) {
-      $max_stdout_read_bytes = $read_buffer_size - strlen($this->stdout);
+      $stdout_len = $this->getStdoutBufferLength();
-      $max_stderr_read_bytes = $read_buffer_size - strlen($this->stderr);
+      $stderr_len = $this->getStderrBufferLength();
+
+      $max_stdout_read_bytes = $read_buffer_size - $stdout_len;
+      $max_stderr_read_bytes = $read_buffer_size - $stderr_len;
     }
 
     if ($max_stdout_read_bytes > 0) {
       $this->stdout .= $this->readAndDiscard(
         $stdout,
-        $this->getStdoutSizeLimit() - strlen($this->stdout),
+        $this->getStdoutSizeLimit() - $this->getStdoutBufferLength(),
         'stdout',
         $max_stdout_read_bytes);
     }
@@ -772,7 +790,7 @@ final class ExecFuture extends PhutilExecutableFuture {
     if ($max_stderr_read_bytes > 0) {
       $this->stderr .= $this->readAndDiscard(
         $stderr,
-        $this->getStderrSizeLimit() - strlen($this->stderr),
+        $this->getStderrSizeLimit() - $this->getStderrBufferLength(),
         'stderr',
         $max_stderr_read_bytes);
     }
@@ -1013,5 +1031,20 @@ final class ExecFuture extends PhutilExecutableFuture {
     );
   }
 
+  private function getStdoutBufferLength() {
+    if ($this->stdout === null) {
+      return 0;
+    }
+
+    return strlen($this->stdout);
+  }
+
+  private function getStderrBufferLength() {
+    if ($this->stderr === null) {
+      return 0;
+    }
+
+    return strlen($this->stderr);
+  }
 
 }

src/future/exec/PhutilExecPassthru.php

@@ -10,8 +10,8 @@
  * This is primarily useful for executing things like `$EDITOR` from command
  * line scripts.
  *
- *   $exec = new PhutilExecPassthru('ls %s', $dir);
+ *   $exec = new PhutilExecPassthru('nano -- %s', $filename);
- *   $err = $exec->execute();
+ *   $err = $exec->resolve();
  *
  * You can set the current working directory for the command with
  * @{method:setCWD}, and set the environment with @{method:setEnv}.
@@ -30,6 +30,14 @@ final class PhutilExecPassthru extends PhutilExecutableFuture {
 /* -(  Executing Passthru Commands  )---------------------------------------- */
 
 
+  public function execute() {
+    phlog(
+      pht(
+        'The "execute()" method of "PhutilExecPassthru" is deprecated and '.
+        'calls should be replaced with "resolve()". See T13660.'));
+    return $this->resolve();
+  }
+
   /**
    * Execute this command.
    *
@@ -37,7 +45,7 @@ final class PhutilExecPassthru extends PhutilExecutableFuture {
    *
    * @task command
    */
-  public function execute() {
+  private function executeCommand() {
     $command = $this->getCommand();
 
     $is_write = ($this->stdinData !== null);
@@ -45,10 +53,14 @@ final class PhutilExecPassthru extends PhutilExecutableFuture {
     if ($is_write) {
       $stdin_spec = array('pipe', 'r');
     } else {
-      $stdin_spec = STDIN;
+      $stdin_spec = PhutilSystem::getStdinHandle();
     }
 
-    $spec = array($stdin_spec, STDOUT, STDERR);
+    $spec = array(
+      $stdin_spec,
+      PhutilSystem::getStdoutHandle(),
+      PhutilSystem::getStderrHandle(),
+    );
     $pipes = array();
 
     $unmasked_command = $command->getUnmaskedString();
@@ -116,7 +128,7 @@ final class PhutilExecPassthru extends PhutilExecutableFuture {
     // make it easier to share code with ExecFuture.
 
     if (!$this->hasResult()) {
-      $result = $this->execute();
+      $result = $this->executeCommand();
       $this->setResult($result);
     }
 

src/future/exec/PhutilExecutableFuture.php

@@ -19,7 +19,7 @@ abstract class PhutilExecutableFuture extends Future {
           pht(
             'Command (of class "%s") was constructed with a '.
             '"PhutilCommandString", but also passed arguments. '.
-            'When using a preprebuilt command, you must not pass '.
+            'When using a prebuilt command, you must not pass '.
             'arguments.',
             get_class($this)));
       }

src/future/exec/__tests__/ExecPassthruTestCase.php

@@ -11,7 +11,7 @@ final class ExecPassthruTestCase extends PhutilTestCase {
     $bin = $this->getSupportExecutable('exit');
 
     $exec = new PhutilExecPassthru('php -f %R', $bin);
-    $err = $exec->execute();
+    $err = $exec->resolve();
     $this->assertEqual(0, $err);
   }
 

src/future/http/BaseHTTPFuture.php

@@ -206,12 +206,14 @@ abstract class BaseHTTPFuture extends Future {
    * @task config
    */
   public function getHeaders($filter = null) {
-    $filter = strtolower($filter);
+    if ($filter !== null) {
+      $filter = phutil_utf8_strtolower($filter);
+    }
 
     $result = array();
     foreach ($this->headers as $header) {
       list($name, $value) = $header;
-      if (!$filter || ($filter == strtolower($name))) {
+      if (($filter === null) || ($filter === phutil_utf8_strtolower($name))) {
         $result[] = $header;
       }
     }

src/future/http/HTTPSFuture.php

@@ -269,7 +269,7 @@ final class HTTPSFuture extends BaseHTTPFuture {
         curl_setopt($curl, CURLOPT_REDIR_PROTOCOLS, $allowed_protocols);
       }
 
-      if (strlen($this->rawBody)) {
+      if ($this->rawBody !== null) {
         if ($this->getData()) {
           throw new Exception(
             pht(

src/init/lib/moduleutils.php

@@ -36,18 +36,6 @@ function phutil_get_current_library_name() {
   return phutil_get_library_name_for_root($root);
 }
 
-/**
- * Warns about use of deprecated behavior.
- */
-function phutil_deprecated($what, $why) {
-  PhutilErrorHandler::dispatchErrorMessage(
-    PhutilErrorHandler::DEPRECATED,
-    $what,
-    array(
-      'why' => $why,
-    ));
-}
-
 function phutil_load_library($path) {
   PhutilBootloader::getInstance()->loadLibrary($path);
 }

src/internationalization/pht.php

@@ -44,3 +44,7 @@ function phutil_count($countable) {
 function phutil_person(PhutilPerson $person) {
   return $person;
 }
+
+function pht_list(array $items) {
+  return implode(', ', $items);
+}

src/land/engine/ArcanistLandEngine.php

@@ -1407,6 +1407,21 @@ abstract class ArcanistLandEngine
     ArcanistLandCommitSet $set,
     $into_commit);
   abstract protected function pushChange($into_commit);
+
+  /**
+   * Update all local refs that depend on refs selected-and-modified during the
+   * land. E.g. with branches named change1 -> change2 -> change3 and using
+   * `arc land change2`, in the general case the local change3 should be
+   * rebased onto the landed version of change2 so that it no longer has
+   * out-of-date ancestors.
+   *
+   * When multiple revisions are landed at once this will be called in a loop
+   * for each set, in order of max to min, where max is the latest descendant
+   * and min is the earliest ancestor. This is done so that non-landing commits
+   * that are descendants of the latest revision will only be rebased once.
+   *
+   * @param ArcanistLandCommitSet  The current commit set to cascade.
+   */
   abstract protected function cascadeState(
     ArcanistLandCommitSet $set,
     $into_commit);
@@ -1415,12 +1430,35 @@ abstract class ArcanistLandEngine
     return ($this->getStrategy() === 'squash');
   }
 
+  /**
+   * Prunes the given sets of commits. This should be called after the sets
+   * have been merged.
+   *
+   * @param array  The list of ArcanistLandCommitSet to prune, in order of
+   *   min to max commit set, where min is the earliest ancestor and max
+   *   is the latest descendant.
+   */
   abstract protected function pruneBranches(array $sets);
 
+  /**
+   * Restore the local repository to an expected state after landing. This
+   * should only be called after all changes have been merged, pruned, and
+   * pushed.
+   *
+   * @param string  The commit hash that was landed into.
+   * @param ArcanistRepositoryLocalState  The local state that was captured
+   *   at the beginning of the land process. This may include stashed changes.
+   */
   abstract protected function reconcileLocalState(
     $into_commit,
     ArcanistRepositoryLocalState $state);
 
+  /**
+   * Display information to the user about how to proceed since the land
+   * process was not fully completed. The merged branch has not been pushed.
+   *
+   * @param string  The commit hash that was landed into.
+   */
   abstract protected function didHoldChanges($into_commit);
 
   private function selectMergeStrategy() {

src/land/engine/ArcanistMercurialLandEngine.php

@@ -6,6 +6,8 @@ final class ArcanistMercurialLandEngine
   private $ontoBranchMarker;
   private $ontoMarkers;
 
+  private $rebasedActiveCommit;
+
   protected function getDefaultSymbols() {
     $api = $this->getRepositoryAPI();
     $log = $this->getLogEngine();
@@ -698,8 +700,14 @@ final class ArcanistMercurialLandEngine
     $commit_map = array();
     foreach ($symbols as $symbol) {
       $symbol_commit = $symbol->getCommit();
-      $template = '{node}-{parents}-';
+      $template = '{node}-{parents % \'{node} \'}-{desc|firstline}\\n';
 
+      // The returned array of commits is expected to be ordered by max to min
+      // where the max commit has no descendants in the range and the min
+      // commit has no ancestors in the range. Use 'reverse()' in the template
+      // so the output is ordered with the max commit as the first line. The
+      // max/min terms are used in a topological sense as chronological terms
+      // for commits may be misleading or incorrect in some situations.
       if ($into_commit === null) {
         list($commits) = $api->execxLocal(
           'log --rev %s --template %s --',
@@ -789,8 +797,14 @@ final class ArcanistMercurialLandEngine
 
     $commits = $set->getCommits();
 
-    $min_commit = last($commits)->getHash();
+    // confirmCommits() reverses the order of the commits as they're ordered
-    $max_commit = head($commits)->getHash();
+    // above in selectCommits(). Now the head of the list is the min commit and
+    // the last is the max commit, where within the range the max commit has no
+    // descendants and the min commit has no ancestors. The min/max terms are
+    // used in a topological sense as chronological terms for commits can be
+    // misleading or incorrect in certain situations.
+    $min_commit = head($commits)->getHash();
+    $max_commit = last($commits)->getHash();
 
     $revision_ref = $set->getRevisionRef();
     $commit_message = $revision_ref->getCommitMessage();
@@ -820,13 +834,19 @@ final class ArcanistMercurialLandEngine
       $argv[] = '--keep';
       $argv[] = '--collapse';
 
-      $future = $api->execFutureLocal('rebase %Ls', $argv);
+      $future = $api->execFutureLocalWithExtension(
+        'rebase',
+        'rebase %Ls',
+        $argv);
       $future->write($commit_message);
       $future->resolvex();
 
     } catch (CommandException $ex) {
-      // TODO
+      // Aborting the rebase should restore the same state prior to running the
-      // $api->execManualLocal('rebase --abort');
+      // rebase command.
+      $api->execManualLocalWithExtension(
+        'rebase',
+        'rebase --abort');
       throw $ex;
     }
 
@@ -855,13 +875,21 @@ final class ArcanistMercurialLandEngine
     list($stdout) = $api->execxLocal('log --rev tip --template %s', '{node}');
     $new_cursor = trim($stdout);
 
+    // If any of the commits that were rebased was the active commit before the
+    // workflow started, track the new commit so it can be used as the working
+    // directory after the land has succeeded.
+    if (isset($obsolete_map[$this->getLocalState()->getLocalCommit()])) {
+      $this->rebasedActiveCommit = $new_cursor;
+    }
+
     return $new_cursor;
   }
 
   protected function pushChange($into_commit) {
     $api = $this->getRepositoryAPI();
 
-    list($head, $body, $tail) = $this->newPushCommands($into_commit);
+    list($head, $body, $tail_pass, $tail_fail) = $this->newPushCommands(
+      $into_commit);
 
     foreach ($head as $command) {
       $api->execxLocal('%Ls', $command);
@@ -876,10 +904,20 @@ final class ArcanistMercurialLandEngine
               'Push failed! Fix the error and run "arc land" again.'));
         }
       }
-    } finally {
+
-      foreach ($tail as $command) {
+      foreach ($tail_pass as $command) {
         $api->execxLocal('%Ls', $command);
       }
+    } catch (Exception $ex) {
+      foreach ($tail_fail as $command) {
+        $api->execxLocal('%Ls', $command);
+      }
+      throw $ex;
+    } catch (Throwable $ex) {
+      foreach ($tail_fail as $command) {
+        $api->execxLocal('%Ls', $command);
+      }
+      throw $ex;
     }
   }
 
@@ -888,7 +926,8 @@ final class ArcanistMercurialLandEngine
 
     $head_commands = array();
     $body_commands = array();
-    $tail_commands = array();
+    $tail_pass_commands = array();
+    $tail_fail_commands = array();
 
     $bookmarks = array();
     foreach ($this->ontoMarkers as $onto_marker) {
@@ -902,7 +941,7 @@ final class ArcanistMercurialLandEngine
     // to the merge commit. (There doesn't seem to be any way to specify
     // "push commit X as bookmark Y" in Mercurial.)
 
-    $restore = array();
+    $restore_bookmarks = array();
     if ($bookmarks) {
       $markers = $api->newMarkerRefQuery()
         ->withNames(mpull($bookmarks, 'getName'))
@@ -934,7 +973,9 @@ final class ArcanistMercurialLandEngine
           hgsprintf('%s', $new_position),
           $bookmark_name);
 
-        $restore[$bookmark_name] = $old_position;
+        if ($old_position !== null) {
+          $restore_bookmarks[$bookmark_name] = $old_position;
+        }
       }
     }
 
@@ -963,28 +1004,41 @@ final class ArcanistMercurialLandEngine
 
     // Finally, restore the bookmarks.
 
-    foreach ($restore as $bookmark_name => $old_position) {
+    if ($restore_bookmarks) {
-      $tail = array();
+      // Instead of restoring the previous state, assume landing onto bookmarks
-      $tail[] = 'bookmark';
+      // also updates those bookmarks in the remote. After pushing, pull the
+      // latest state of these bookmarks. Mercurial allows pulling multiple
+      // bookmarks in a single pull command which will be faster than pulling
+      // them from a remote individually.
+      $tail = array(
+        'pull',
+      );
 
-      if ($old_position === null) {
+      foreach ($restore_bookmarks as $bookmark_name => $old_position) {
-        $tail[] = '--delete';
+        $tail[] = '--bookmark';
-      } else {
-        $tail[] = '--force';
-        $tail[] = '--rev';
-        $tail[] = hgsprintf('%s', $api->getDisplayHash($old_position));
-      }
-
-      $tail[] = '--';
         $tail[] = $bookmark_name;
 
-      $tail_commands[] = $tail;
+        // In the failure case restore the state of the bookmark. Mercurial
+        // does not provide a way to move multiple bookmarks in a single
+        // command however these commands do not involve the remote.
+        $tail_fail_commands[] = array(
+          'bookmark',
+          '--force',
+          '--rev',
+          hgsprintf('%s', $api->getDisplayHash($old_position)),
+        );
+      }
+
+      if ($tail) {
+        $tail_pass_commands[] = $tail;
+      }
     }
 
     return array(
       $head_commands,
       $body_commands,
-      $tail_commands,
+      $tail_pass_commands,
+      $tail_fail_commands,
     );
   }
 
@@ -1015,12 +1069,17 @@ final class ArcanistMercurialLandEngine
       // be deleted, we can skip this rebase?
 
       try {
-        $api->execxLocal(
+        $api->execxLocalWithExtension(
+          'rebase',
           'rebase --source %s --dest %s --keep --keepbranches',
           $child_hash,
           $new_commit);
       } catch (CommandException $ex) {
-        // TODO: Recover state.
+        // Aborting the rebase should restore the same state prior to running
+        // the rebase command.
+        $api->execManualLocalWithExtension(
+          'rebase',
+          'rebase --abort');
         throw $ex;
       }
     }
@@ -1040,6 +1099,8 @@ final class ArcanistMercurialLandEngine
     $revs = array();
     $obsolete_map = array();
 
+    $using_evolve = $api->getMercurialFeature('evolve');
+
     // We've rebased all descendants already, so we can safely delete all
     // of these commits.
 
@@ -1047,10 +1108,22 @@ final class ArcanistMercurialLandEngine
     foreach ($sets as $set) {
       $commits = $set->getCommits();
 
+      // In the commit set the min commit should be the commit with no
+      // ancestors and the max commit should be the commit with no descendants.
+      // The min/max terms are used in a toplogical sense as chronological
+      // terms for commits may be misleading or incorrect in some situations.
       $min_commit = head($commits)->getHash();
       $max_commit = last($commits)->getHash();
 
+      if ($using_evolve) {
+        // If non-head series of commits are rebased while the evolve extension
+        // is in use, the rebase leaves behind the entire series of descendants
+        // in which case the entire chain needs removed, not just a section.
+        // Otherwise this results in the prune leaving behind orphaned commits.
+        $revs[] = hgsprintf('%s::', $min_commit);
+      } else {
         $revs[] = hgsprintf('%s::%s', $min_commit, $max_commit);
+      }
 
       foreach ($commits as $commit) {
         $obsolete_map[$commit->getHash()] = true;
@@ -1071,10 +1144,7 @@ final class ArcanistMercurialLandEngine
     // bookmarks which point at these now-obsoleted commits.
 
     $bookmark_refs = $api->newMarkerRefQuery()
-      ->withMarkerTypes(
+      ->withMarkerTypes(array(ArcanistMarkerRef::TYPE_BOOKMARK))
-        array(
-          ArcanistMarkerRef::TYPE_BOOKMARK,
-        ))
       ->execute();
     foreach ($bookmark_refs as $bookmark_ref) {
       $bookmark_hash = $bookmark_ref->getCommitHash();
@@ -1093,13 +1163,14 @@ final class ArcanistMercurialLandEngine
         $bookmark_name);
     }
 
-    if ($api->getMercurialFeature('evolve')) {
+    if ($using_evolve) {
       $api->execxLocal(
         'prune --rev %s',
         $rev_set);
     } else {
-      $api->execxLocal(
+      $api->execxLocalWithExtension(
-        '--config extensions.strip= strip --rev %s',
+        'strip',
+        'strip --rev %s',
         $rev_set);
     }
   }
@@ -1108,7 +1179,54 @@ final class ArcanistMercurialLandEngine
     $into_commit,
     ArcanistRepositoryLocalState $state) {
 
-    // TODO: For now, just leave users wherever they ended up.
+    $api = $this->getRepositoryAPI();
+
+    // If the starting working state was not part of land process just update
+    // to that original working state.
+    if ($this->rebasedActiveCommit === null) {
+      $update_marker = $this->getLocalState()->getLocalCommit();
+      if ($this->getLocalState()->getLocalBookmark() !== null) {
+        $update_marker = $this->getLocalState()->getLocalBookmark();
+      }
+
+      $api->execxLocal(
+        'update -- %s',
+        $update_marker);
+
+      $state->discardLocalState();
+      return;
+    }
+
+    // If the working state was landed into multiple destinations then the
+    // resulting working state is ambiguous.
+    if (count($this->ontoMarkers) != 1) {
+      $state->discardLocalState();
+      return;
+    }
+
+    // Get the current state of bookmarks
+    $bookmark_refs = $api->newMarkerRefQuery()
+      ->withMarkerTypes(array(ArcanistMarkerRef::TYPE_BOOKMARK))
+      ->execute();
+
+    $update_marker = $this->rebasedActiveCommit;
+
+    // Find any bookmarks which exist on the commit which is the result of the
+    // starting working directory's rebase. If any of those bookmarks are also
+    // the destination marker then we use that bookmark as the update in order
+    // for it to become active.
+    $onto_marker = $this->ontoMarkers[0]->getName();
+    foreach ($bookmark_refs as $bookmark_ref) {
+      if ($bookmark_ref->getCommitHash() == $this->rebasedActiveCommit &&
+        $bookmark_ref->getName() == $onto_marker) {
+          $update_marker = $onto_marker;
+          break;
+      }
+    }
+
+    $api->execxLocal(
+      'update -- %s',
+      $update_marker);
 
     $state->discardLocalState();
   }
@@ -1120,8 +1238,9 @@ final class ArcanistMercurialLandEngine
     $message = pht(
       'Holding changes locally, they have not been pushed.');
 
-    list($head, $body, $tail) = $this->newPushCommands($into_commit);
+    list($head, $body, $tail_pass, $tail_fail) = $this->newPushCommands(
-    $commands = array_merge($head, $body, $tail);
+      $into_commit);
+    $commands = array_merge($head, $body, $tail_pass);
 
     echo tsprintf(
       "\n%!\n%s\n\n",

src/lint/linter/ArcanistCSharpLinter.php

@@ -64,11 +64,11 @@ final class ArcanistCSharpLinter extends ArcanistLinter {
         throw new Exception(
           pht(
             "In order to keep StyleCop integration with IDEs and other tools ".
-            "consistent with Arcanist results, you aren't permitted to ".
+            "consistent with lint results, you aren't permitted to ".
             "disable StyleCop rules within '%s'. Instead configure the ".
             "severity using the StyleCop settings dialog (usually accessible ".
             "from within your IDE). StyleCop settings for your project will ".
-            "be used when linting for Arcanist.",
+            "be used when linting.",
             '.arclint'));
       }
     }
@@ -132,8 +132,8 @@ final class ArcanistCSharpLinter extends ArcanistLinter {
     } else if ($ver > self::SUPPORTED_VERSION) {
       throw new Exception(
         pht(
-          'Arcanist does not support this version of %s (it is newer). '.
+          'This version of %s is not supported (it is too new). '.
-          'You can try upgrading Arcanist with `%s`.',
+          'You can try upgrading with `%s`.',
           'cslint',
           'arc upgrade'));
     }

src/lint/linter/ArcanistPhutilLibraryLinter.php

@@ -304,9 +304,9 @@ final class ArcanistPhutilLibraryLinter extends ArcanistLinter {
             $details = pht(
               "Common causes are:\n".
               "\n".
-              "  - Your copy of Arcanist is out of date.\n".
+              "  - Your copy of %s is out of date.\n".
               "    This is the most common cause.\n".
-              "    Update this copy of Arcanist:\n".
+              "    Update this copy of %s:\n".
               "\n".
               "      %s\n".
               "\n".
@@ -324,6 +324,8 @@ final class ArcanistPhutilLibraryLinter extends ArcanistLinter {
               "  - This symbol is defined in an external library.\n".
               "    Use \"@phutil-external-symbol\" to annotate it.\n".
               "    Use \"grep\" to find examples of usage.",
+              PlatformSymbols::getPlatformClientName(),
+              PlatformSymbols::getPlatformClientName(),
               $arcanist_root);
 
             $message = implode(

src/lint/linter/ArcanistXMLLinter.php

@@ -27,7 +27,11 @@ final class ArcanistXMLLinter extends ArcanistLinter {
   }
 
   public function getCacheVersion() {
+    if (defined('LIBXML_VERSION')) {
       return LIBXML_VERSION;
+    } else {
+      return 'unavailable';
+    }
   }
 
   public function lintPath($path) {

src/lint/linter/__tests__/ArcanistLinterTestCase.php

@@ -51,6 +51,13 @@ abstract class ArcanistLinterTestCase extends PhutilTestCase {
   private function lintFile($file, ArcanistLinter $linter) {
     $linter = clone $linter;
 
+    if (!$linter->canRun()) {
+      $this->assertSkipped(
+        pht(
+          'Linter "%s" can not run.',
+          get_class($linter)));
+    }
+
     $contents = Filesystem::readFile($file);
     $contents = preg_split('/^~{4,}\n/m', $contents);
     if (count($contents) < 2) {
@@ -283,9 +290,12 @@ abstract class ArcanistLinterTestCase extends PhutilTestCase {
   }
 
   private function compareTransform($expected, $actual) {
+    $expected = phutil_string_cast($expected);
+
     if (!strlen($expected)) {
       return;
     }
+
     $this->assertEqual(
       $expected,
       $actual,

src/lint/linter/xhpast/rules/ArcanistCommentStyleXHPASTLinterRule.php

@@ -17,6 +17,14 @@ final class ArcanistCommentStyleXHPASTLinterRule
         continue;
       }
 
+      // Don't warn about PHP comment directives. In particular, we need
+      // to use "#[\ReturnTypeWillChange]" to implement "Iterator" in a way
+      // that is compatible with PHP 8.1 and older versions of PHP prior
+      // to the introduction of return types. See T13588.
+      if (preg_match('/^#\\[\\\\/', $value)) {
+        continue;
+      }
+
       $this->raiseLintAtOffset(
         $comment->getOffset(),
         pht(

src/lint/linter/xhpast/rules/ArcanistEachUseXHPASTLinterRule.php

@@ -0,0 +1,24 @@
+<?php
+
+final class ArcanistEachUseXHPASTLinterRule
+  extends ArcanistXHPASTLinterRule {
+
+  const ID = 133;
+
+  public function getLintName() {
+    return pht('Use of Removed Function "each()"');
+  }
+
+  public function process(XHPASTNode $root) {
+    $calls = $this->getFunctionCalls($root, array('each'));
+
+    foreach ($calls as $call) {
+      $this->raiseLintAtNode(
+        $call,
+        pht(
+          'Do not use "each()". This function was deprecated in PHP 7.2 '.
+          'and removed in PHP 8.0'));
+    }
+  }
+
+}

src/lint/linter/xhpast/rules/ArcanistPHPCompatibilityXHPASTLinterRule.php

@@ -155,7 +155,9 @@ final class ArcanistPHPCompatibilityXHPASTLinterRule
       if ($this->windowsVersion) {
         $windows = idx($compat_info['functions_windows'], $name);
 
-        if ($windows === false) {
+        if ($windows === null) {
+          // This function has no special Windows considerations.
+        } else if ($windows === false) {
           $this->raiseLintAtNode(
             $node,
             pht(

src/lint/linter/xhpast/rules/ArcanistParentMemberReferenceXHPASTLinterRule.php

@@ -55,7 +55,12 @@ final class ArcanistParentMemberReferenceXHPASTLinterRule
             }
           }
 
-          if (version_compare($this->version, '5.4.0', '>=') || !$in_closure) {
+          $version_target = $this->version;
+          if ($version_target === null) {
+            $version_target = phpversion();
+          }
+
+          if (version_compare($version_target, '5.4.0', '>=') || !$in_closure) {
             $this->raiseLintAtNode(
               $class_ref,
               pht(

src/lint/linter/xhpast/rules/ArcanistProductNameLiteralXHPASTLinterRule.php

@@ -0,0 +1,67 @@
+<?php
+
+final class ArcanistProductNameLiteralXHPASTLinterRule
+  extends ArcanistXHPASTLinterRule {
+
+  const ID = 134;
+
+  public function getLintName() {
+    return pht('Use of Product Name Literal');
+  }
+
+  public function getLintSeverity() {
+    return ArcanistLintSeverity::SEVERITY_WARNING;
+  }
+
+  public function process(XHPASTNode $root) {
+    $calls = $root->selectDescendantsOfType('n_FUNCTION_CALL');
+
+    $product_names = PlatformSymbols::getProductNames();
+    foreach ($product_names as $k => $product_name) {
+      $product_names[$k] = preg_quote($product_name);
+    }
+
+    $search_pattern = '(\b(?:'.implode('|', $product_names).')\b)i';
+
+    foreach ($calls as $call) {
+      $name = $call->getChildByIndex(0)->getConcreteString();
+
+      if ($name !== 'pht') {
+        continue;
+      }
+
+      $parameters = $call->getChildByIndex(1);
+
+      if (!$parameters->getChildren()) {
+        continue;
+      }
+
+      $identifier = $parameters->getChildByIndex(0);
+      if (!$identifier->isConstantString()) {
+        continue;
+      }
+
+      $literal_value = $identifier->evalStatic();
+
+      $matches = phutil_preg_match_all($search_pattern, $literal_value);
+      if (!$matches[0]) {
+        continue;
+      }
+
+      $name_list = array();
+      foreach ($matches[0] as $match) {
+        $name_list[phutil_utf8_strtolower($match)] = $match;
+      }
+      $name_list = implode(', ', $name_list);
+
+      $this->raiseLintAtNode(
+        $identifier,
+        pht(
+          'Avoid use of product name literals in "pht()": use generic '.
+          'language or an appropriate method from the "PlatformSymbols" class '.
+          'instead so the software can be forked. String uses names: %s.',
+          $name_list));
+    }
+  }
+
+}

src/lint/linter/xhpast/rules/ArcanistSelfMemberReferenceXHPASTLinterRule.php

@@ -42,7 +42,12 @@ final class ArcanistSelfMemberReferenceXHPASTLinterRule
             }
           }
 
-          if (version_compare($this->version, '5.4.0', '>=') || !$in_closure) {
+          $version_target = $this->version;
+          if (!$version_target) {
+            $version_target = phpversion();
+          }
+
+          if (version_compare($version_target, '5.4.0', '>=') || !$in_closure) {
             $this->raiseLintAtNode(
               $class_ref,
               pht(

src/lint/linter/xhpast/rules/__tests__/ArcanistEachUseXHPASTLinterRuleTestCase.php

@@ -0,0 +1,10 @@
+<?php
+
+final class ArcanistEachUseXHPASTLinterRuleTestCase
+  extends ArcanistXHPASTLinterRuleTestCase {
+
+  public function testLinter() {
+    $this->executeTestsInDirectory(dirname(__FILE__).'/each-use/');
+  }
+
+}

src/lint/linter/xhpast/rules/__tests__/comment-style/hash-directives.lint-test

@@ -0,0 +1,23 @@
+<?php
+
+class X implements Iterator {
+
+  #[\ReturnTypeWillChange]
+  public function reset() {
+    # See T13588 for PHP8.1 compatibility information.
+  }
+
+}
+~~~~~~~~~~
+error:7:5:XHP18:Comment Style
+~~~~~~~~~~
+<?php
+
+class X implements Iterator {
+
+  #[\ReturnTypeWillChange]
+  public function reset() {
+    // See T13588 for PHP8.1 compatibility information.
+  }
+
+}

src/lint/linter/xhpast/rules/__tests__/each-use/each.lint-test

@@ -0,0 +1,6 @@
+<?php
+
+$a = range(1, 2);
+each($a);
+~~~~~~~~~~
+error:4:1:XHP133

src/lint/renderer/ArcanistConsoleLintRenderer.php

@@ -112,6 +112,8 @@ final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
     $message = $message->newTrimmedMessage();
 
     $original = $message->getOriginalText();
+    $original = phutil_string_cast($original);
+
     $replacement = $message->getReplacementText();
 
     $line = $message->getLine();

src/log/ArcanistLogEngine.php

@@ -19,7 +19,7 @@ final class ArcanistLogEngine
   }
 
   private function writeBytes($bytes) {
-    fprintf(STDERR, '%s', $bytes);
+    PhutilSystem::writeStderr($bytes);
     return $this;
   }
 

src/moduleutils/PhutilLibraryMapBuilder.php

@@ -12,7 +12,6 @@
 final class PhutilLibraryMapBuilder extends Phobject {
 
   private $root;
-  private $quiet = true;
   private $subprocessLimit = 8;
 
   private $fileSymbolMap;
@@ -38,19 +37,6 @@ final class PhutilLibraryMapBuilder extends Phobject {
     $this->root = $root;
   }
 
-  /**
-   * Control status output. Use `--quiet` to set this.
-   *
-   * @param  bool  If true, don't show status output.
-   * @return this
-   *
-   * @task map
-   */
-  public function setQuiet($quiet) {
-    $this->quiet = $quiet;
-    return $this;
-  }
-
   /**
    * Control subprocess parallelism limit. Use `--limit` to set this.
    *
@@ -108,25 +94,9 @@ final class PhutilLibraryMapBuilder extends Phobject {
   public function buildAndWriteMap() {
     $library_map = $this->buildMap();
 
-    $this->log(pht('Writing map...'));
     $this->writeLibraryMap($library_map);
   }
 
-  /**
-   * Write a status message to the user, if not running in quiet mode.
-   *
-   * @param  string  Message to write.
-   * @return this
-   *
-   * @task map
-   */
-  private function log($message) {
-    if (!$this->quiet) {
-      @fprintf(STDERR, "%s\n", $message);
-    }
-    return $this;
-  }
-
 
 /* -(  Path Management  )---------------------------------------------------- */
 
@@ -236,11 +206,7 @@ final class PhutilLibraryMapBuilder extends Phobject {
     }
 
     $json = json_encode($cache);
-    try {
     Filesystem::writeFile($cache_file, $json);
-    } catch (FilesystemException $ex) {
-      $this->log(pht('Unable to save the cache!'));
-    }
   }
 
   /**
@@ -251,7 +217,6 @@ final class PhutilLibraryMapBuilder extends Phobject {
    * @task symbol
    */
   public function dropSymbolCache() {
-    $this->log(pht('Dropping symbol cache...'));
     Filesystem::remove($this->getPathForSymbolCache());
   }
 
@@ -451,14 +416,10 @@ EOPHP;
    */
   private function analyzeLibrary() {
     // Identify all the ".php" source files in the library.
-    $this->log(pht('Finding source files...'));
     $source_map = $this->loadSourceFileMap();
-    $this->log(
-      pht('Found %s files.', new PhutilNumber(count($source_map))));
 
     // Load the symbol cache with existing parsed symbols. This allows us
     // to remap libraries quickly by analyzing only changed files.
-    $this->log(pht('Loading symbol cache...'));
     $symbol_cache = $this->loadSymbolCache();
 
     // If the XHPAST binary is not up-to-date, build it now. Otherwise,
@@ -481,23 +442,12 @@ EOPHP;
       }
       $futures[$file] = $this->buildSymbolAnalysisFuture($file);
     }
-    $this->log(
-      pht('Found %s files in cache.', new PhutilNumber(count($symbol_map))));
 
     // Run the analyzer on any files which need analysis.
     if ($futures) {
       $limit = $this->subprocessLimit;
 
-      $this->log(
-        pht(
-          'Analyzing %s file(s) with %s subprocess(es)...',
-          phutil_count($futures),
-          new PhutilNumber($limit)));
-
       $progress = new PhutilConsoleProgressBar();
-      if ($this->quiet) {
-        $progress->setQuiet(true);
-      }
       $progress->setTotal(count($futures));
 
       $futures = id(new FutureIterator($futures))
@@ -525,8 +475,6 @@ EOPHP;
     $this->writeSymbolCache($symbol_map, $source_map);
 
     // Our map is up to date, so either show it on stdout or write it to disk.
-    $this->log(pht('Building library map...'));
-
     $this->librarySymbolMap = $this->buildLibraryMap($symbol_map);
   }
 

src/object/Phobject.php

@@ -33,22 +33,27 @@ abstract class Phobject implements Iterator {
         get_class($this).'::'.$name));
   }
 
+  #[\ReturnTypeWillChange]
   public function current() {
     $this->throwOnAttemptedIteration();
   }
 
+  #[\ReturnTypeWillChange]
   public function key() {
     $this->throwOnAttemptedIteration();
   }
 
+  #[\ReturnTypeWillChange]
   public function next() {
     $this->throwOnAttemptedIteration();
   }
 
+  #[\ReturnTypeWillChange]
   public function rewind() {
     $this->throwOnAttemptedIteration();
   }
 
+  #[\ReturnTypeWillChange]
   public function valid() {
     $this->throwOnAttemptedIteration();
   }

src/parser/ArcanistBaseCommitParser.php

@@ -33,7 +33,7 @@ final class ArcanistBaseCommitParser extends Phobject {
 
   private function log($message) {
     if ($this->verbose) {
-      fwrite(STDERR, $message."\n");
+      PhutilSystem::writeStderr($message."\n");
     }
   }
 

src/parser/ArcanistBundle.php

@@ -639,8 +639,7 @@ final class ArcanistBundle extends Phobject {
     $old_path = $change->getOldPath();
     $type = $change->getType();
 
-    if (!strlen($old_path) ||
+    if ($old_path === '' || $type == ArcanistDiffChangeType::TYPE_ADD) {
-        $type == ArcanistDiffChangeType::TYPE_ADD) {
       $old_path = null;
     }
 
@@ -1023,7 +1022,7 @@ final class ArcanistBundle extends Phobject {
         if ($is_64bit) {
           for ($count = 4; $count >= 0; $count--) {
             $val = $accum % 85;
-            $accum = $accum / 85;
+            $accum = (int)($accum / 85);
             $slice .= $map[$val];
           }
         } else {

src/parser/ArcanistDiffParser.php

@@ -217,7 +217,7 @@ final class ArcanistDiffParser extends Phobject {
       $line = $this->nextLine();
     }
 
-    if (strlen($message)) {
+    if ($message !== null && strlen($message)) {
       // If we found a message during pre-parse steps, add it to the resulting
       // changes here.
       $change = $this->buildChange(null)
@@ -582,12 +582,15 @@ final class ArcanistDiffParser extends Phobject {
 
         $ok = false;
         $match = null;
+
+        if ($line !== null) {
           foreach ($patterns as $pattern) {
             $ok = preg_match('@^'.$pattern.'@', $line, $match);
             if ($ok) {
               break;
             }
           }
+        }
 
         if (!$ok) {
           if ($line === null ||
@@ -774,7 +777,7 @@ final class ArcanistDiffParser extends Phobject {
       $this->nextLine();
       $this->parseGitBinaryPatch();
       $line = $this->getLine();
-      if (preg_match('/^literal/', $line)) {
+      if ($line !== null && preg_match('/^literal/', $line)) {
         // We may have old/new binaries (change) or just a new binary (hg add).
         // If there are two blocks, parse both.
         $this->parseGitBinaryPatch();
@@ -920,11 +923,11 @@ final class ArcanistDiffParser extends Phobject {
       $hunk->setNewOffset($matches[3]);
 
       // Cover for the cases where length wasn't present (implying one line).
-      $old_len = idx($matches, 2);
+      $old_len = idx($matches, 2, '');
       if (!strlen($old_len)) {
         $old_len = 1;
       }
-      $new_len = idx($matches, 4);
+      $new_len = idx($matches, 4, '');
       if (!strlen($new_len)) {
         $new_len = 1;
       }
@@ -1041,7 +1044,7 @@ final class ArcanistDiffParser extends Phobject {
         $line = $this->nextNonemptyLine();
       }
 
-    } while (preg_match('/^@@ /', $line));
+    } while (($line !== null) && preg_match('/^@@ /', $line));
   }
 
   protected function buildChange($path = null) {

src/parser/PhutilBugtraqParser.php

@@ -85,7 +85,7 @@ final class PhutilBugtraqParser extends Phobject {
       $captured_text = $capture['text'];
       $captured_offset = $capture['at'];
 
-      if (strlen($select_regexp)) {
+      if ($select_regexp !== null) {
         $selections = null;
         preg_match_all(
           $select_regexp,

src/parser/PhutilEmailAddress.php

@@ -13,6 +13,7 @@ final class PhutilEmailAddress extends Phobject {
   private $domainName;
 
   public function __construct($email_address = null) {
+    $email_address = phutil_string_cast($email_address);
     $email_address = trim($email_address);
 
     $matches = null;
@@ -41,12 +42,13 @@ final class PhutilEmailAddress extends Phobject {
 
   public function __toString() {
     $address = $this->getAddress();
-    if (strlen($this->displayName)) {
+
+    if (phutil_nonempty_string($this->displayName)) {
       $display_name = $this->encodeDisplayName($this->displayName);
       return $display_name.' <'.$address.'>';
-    } else {
-      return $address;
     }
+
+    return $address;
   }
 
   public function setDisplayName($display_name) {
@@ -89,7 +91,7 @@ final class PhutilEmailAddress extends Phobject {
 
   public function getAddress() {
     $address = $this->localPart;
-    if (strlen($this->domainName)) {
+    if ($this->domainName !== null && strlen($this->domainName)) {
       $address .= '@'.$this->domainName;
     }
     return $address;

src/parser/PhutilURI.php

@@ -154,9 +154,9 @@ final class PhutilURI extends Phobject {
 
     $user = $this->user;
     $pass = $this->pass;
-    if (strlen($user) && strlen($pass)) {
+    if (phutil_nonempty_string($user) && phutil_nonempty_string($pass)) {
       $auth = rawurlencode($user).':'.rawurlencode($pass).'@';
-    } else if (strlen($user)) {
+    } else if (phutil_nonempty_string($user)) {
       $auth = rawurlencode($user).'@';
     } else {
       $auth = null;
@@ -166,19 +166,24 @@ final class PhutilURI extends Phobject {
     if ($this->isGitURI()) {
       $protocol = null;
     } else {
-      if (strlen($auth)) {
+      if ($auth !== null) {
         $protocol = nonempty($this->protocol, 'http');
       }
     }
 
-    if (strlen($protocol) || strlen($auth) || strlen($domain)) {
+    $has_protocol = ($protocol !== null) && strlen($protocol);
+    $has_auth = ($auth !== null);
+    $has_domain = ($domain !== null) && strlen($domain);
+    $has_port = ($port !== null) && strlen($port);
+
+    if ($has_protocol || $has_auth || $has_domain) {
       if ($this->isGitURI()) {
         $prefix = "{$auth}{$domain}";
       } else {
         $prefix = "{$protocol}://{$auth}{$domain}";
       }
 
-      if (strlen($port)) {
+      if ($has_port) {
         $prefix .= ':'.$port;
       }
     }
@@ -189,7 +194,7 @@ final class PhutilURI extends Phobject {
       $query = null;
     }
 
-    if (strlen($this->getFragment())) {
+    if (phutil_nonempty_string($this->getFragment())) {
       $fragment = '#'.$this->getFragment();
     } else {
       $fragment = null;
@@ -428,7 +433,7 @@ final class PhutilURI extends Phobject {
     if ($this->isGitURI()) {
       // Git URIs use relative paths which do not need to begin with "/".
     } else {
-      if ($this->domain && strlen($path) && $path[0] !== '/') {
+      if ($this->domain && phutil_nonempty_string($path) && $path[0] !== '/') {
         $path = '/'.$path;
       }
     }

src/parser/aast/api/AASTNodeList.php

@@ -80,6 +80,7 @@ final class AASTNodeList
 
 /* -(  Countable  )---------------------------------------------------------- */
 
+  #[\ReturnTypeWillChange]
   public function count() {
     return count($this->ids);
   }
@@ -87,22 +88,27 @@ final class AASTNodeList
 
 /* -(  Iterator  )----------------------------------------------------------- */
 
+  #[\ReturnTypeWillChange]
   public function current() {
     return $this->list[$this->key()];
   }
 
+  #[\ReturnTypeWillChange]
   public function key() {
     return $this->ids[$this->pos];
   }
 
+  #[\ReturnTypeWillChange]
   public function next() {
     $this->pos++;
   }
 
+  #[\ReturnTypeWillChange]
   public function rewind() {
     $this->pos = 0;
   }
 
+  #[\ReturnTypeWillChange]
   public function valid() {
     return $this->pos < count($this->ids);
   }

src/parser/argument/PhutilArgumentParser.php

@@ -625,6 +625,33 @@ final class PhutilArgumentParser extends Phobject {
     return $this->specs[$name]->getDefault();
   }
 
+  public function getArgAsInteger($name) {
+    $value = $this->getArg($name);
+
+    if ($value === null) {
+      return $value;
+    }
+
+    if (!preg_match('/^-?\d+\z/', $value)) {
+      throw new PhutilArgumentUsageException(
+        pht(
+          'Parameter provided to argument "--%s" must be an integer.',
+          $name));
+    }
+
+    $intvalue = (int)$value;
+
+    if (phutil_string_cast($intvalue) !== phutil_string_cast($value)) {
+      throw new PhutilArgumentUsageException(
+        pht(
+          'Parameter provided to argument "--%s" is too large to '.
+          'parse as an integer.',
+          $name));
+    }
+
+    return $intvalue;
+  }
+
   public function getUnconsumedArgumentVector() {
     return $this->argv;
   }
@@ -769,7 +796,12 @@ final class PhutilArgumentParser extends Phobject {
         pht('There is no **%s** workflow.', $workflow_name));
     } else {
       $out[] = $this->indent($indent, $workflow->getExamples());
+
+      $synopsis = $workflow->getSynopsis();
+      if ($synopsis !== null) {
         $out[] = $this->indent($indent, $workflow->getSynopsis());
+      }
+
       if ($show_details) {
         $full_help = $workflow->getHelp();
         if ($full_help) {
@@ -800,7 +832,7 @@ final class PhutilArgumentParser extends Phobject {
 
 
   private function logMessage($message) {
-    fwrite(STDERR, $message);
+    PhutilSystem::writeStderr($message);
   }
 
 

src/platform/PlatformSymbols.php

@@ -0,0 +1,21 @@
+<?php
+
+final class PlatformSymbols
+  extends Phobject {
+
+  public static function getPlatformClientName() {
+    return 'Arcanist';
+  }
+
+  public static function getPlatformServerName() {
+    return 'Phabricator';
+  }
+
+  public static function getProductNames() {
+    return array(
+      self::getPlatformClientName(),
+      self::getPlatformServerName(),
+    );
+  }
+
+}

src/progress/PhutilConsoleProgressSink.php

@@ -110,6 +110,6 @@ final class PhutilConsoleProgressSink
   }
 
   private function printLine($line) {
-    fprintf(STDERR, '%s', $line);
+    PhutilSystem::writeStderr($line);
   }
 }

src/ref/commit/ArcanistMercurialCommitSymbolCommitHardpointQuery.php

@@ -0,0 +1,204 @@
+<?php
+
+final class ArcanistMercurialCommitSymbolCommitHardpointQuery
+  extends ArcanistWorkflowMercurialHardpointQuery {
+
+  public function getHardpoints() {
+    return array(
+      ArcanistCommitSymbolRef::HARDPOINT_OBJECT,
+    );
+  }
+
+  protected function canLoadRef(ArcanistRef $ref) {
+    return ($ref instanceof ArcanistCommitSymbolRef);
+  }
+
+  public function loadHardpoint(array $refs, $hardpoint) {
+    $symbol_map = array();
+    foreach ($refs as $key => $ref) {
+      $symbol_map[$key] = $ref->getSymbol();
+    }
+
+    $symbol_set = array_fuse($symbol_map);
+    foreach ($symbol_set as $symbol) {
+      $this->validateSymbol($symbol);
+    }
+
+    $api = $this->getRepositoryAPI();
+
+    // Using "hg log" with repeated "--rev arguments will have the following
+    // behaviors which need accounted for:
+    // 1. If any one revision is invalid then the entire command will fail. To
+    //    work around this the revset uses a trick where specifying a pattern
+    //    for the bookmark() or tag() predicates instead of a literal won't
+    //    result in failure if the pattern isn't found.
+    // 2. Multiple markers that resolve to the same node will only be included
+    //    once in the output. Because of this the order of output can't be
+    //    relied upon to match up with the requested symbol. To work around
+    //    this, the template used must also output any associated symbols to
+    //    match back to. Because of this there is no reasonable way to resolve
+    //    symbols with Mercurial-supported modifiers such as 'symbol^'.
+    // 3. The working directory can't be identified directly, instead a special
+    //    template conditional is used to include 'CWD' as the second item in
+    //    the output if the node is also the working directory, or 'NOTCWD'
+    //    otherwise. This needs included before the tags/bookmarks in order to
+    //    distinguish it from some repository using that same name for a tag or
+    //    bookmark.
+
+    $pattern = array();
+    $arguments = array();
+
+    $pattern[] = 'log';
+
+    $pattern[] = '--template %s';
+    $arguments[] = "{rev}\1".
+                   "{node}\1".
+                   "{ifcontains(rev, revset('parents()'), 'CWD', 'NOTCWD')}\1".
+                   "{tags % '{tag}\2'}{bookmarks % '{bookmark}\2'}\3";
+
+    foreach ($symbol_set as $symbol) {
+      // This is the one symbol that wouldn't be a bookmark or tag
+      if ($symbol === '.') {
+        $pattern[] = '--rev .';
+        continue;
+      }
+
+      $predicates = array();
+
+      if (ctype_xdigit($symbol)) {
+        // Commit hashes are 40 characters
+        if (strlen($symbol) <= 40) {
+          $predicates[] = hgsprintf('id("%s")', $symbol);
+        }
+      }
+
+      if (ctype_digit($symbol)) {
+        // This is 2^32-1 which is (typically) the maximum size of an int in
+        // Python -- passing anything higher than this to rev() will result
+        // in a Python exception.
+        if ($symbol <= 2147483647) {
+          $predicates[] = hgsprintf('rev("%s")', $symbol);
+        }
+      } else {
+        // Mercurial disallows using numbers as marker names.
+        $re_symbol = preg_quote($symbol);
+        $predicates[] = hgsprintf('bookmark("re:^%s$")', $re_symbol);
+        $predicates[] = hgsprintf('tag("re:^%s$")', $re_symbol);
+      }
+
+      $pattern[] = '--rev %s';
+      $arguments[] = implode(' or ', $predicates);
+    }
+
+    $pattern = implode(' ', $pattern);
+    array_unshift($arguments, $pattern);
+
+    $future = call_user_func_array(
+      array($api, 'newFuture'),
+      $arguments);
+
+    list($stdout) = (yield $this->yieldFuture($future));
+
+    $lines = explode("\3", $stdout);
+
+    $hash_map = array();
+    $node_list = array();
+
+    foreach ($lines as $line) {
+      $parts = explode("\1", $line, 4);
+
+      if (empty(array_filter($parts))) {
+        continue;
+      } else if (count($parts) === 3) {
+        list($rev, $node, $cwd) = $parts;
+        $markers = array();
+      } else if (count($parts) === 4) {
+        list($rev, $node, $cwd, $markers) = $parts;
+        $markers = array_filter(explode("\2", $markers));
+      } else {
+        throw new Exception(
+          pht('Execution of "hg log" emitted an unexpected line ("%s").',
+            $line));
+      }
+
+      $node_list[] = $node;
+
+      if (in_array($rev, $symbol_set)) {
+        if (!isset($hash_map[$rev])) {
+          $hash_map[$rev] = $node;
+        } else if ($hash_map[$rev] !== $node) {
+          $hash_map[$rev] = '';
+        }
+      }
+
+      foreach ($markers as $marker) {
+        if (!isset($hash_map[$marker])) {
+          $hash_map[$marker] = $node;
+        } else if ($hash_map[$marker] !== $node) {
+          $hash_map[$marker] = '';
+        }
+      }
+
+      // The log template will mark the working directory node with 'CWD' which
+      // we insert for the special marker '.' for the working directory, used
+      // by ArcanistMercurialAPI::newCurrentCommitSymbol().
+      if ($cwd === 'CWD') {
+        if (!isset($hash_map['.'])) {
+          $hash_map['.'] = $node;
+        } else if ($hash_map['.'] !== $node) {
+          $hash_map['.'] = '';
+        }
+      }
+    }
+
+    // Changeset hashes can be prefixes but also collide with other markers.
+    // Consider 'cafe' which could be a bookmark or also a changeset hash
+    // prefix. Mercurial will always allow markers to take precedence over
+    // changeset hashes when resolving, so only populate symbols that match
+    // hashes after all other entries are populated, to avoid the hash taing
+    // a spot which a marker might match.
+    foreach ($node_list as $node) {
+      foreach ($symbol_set as $symbol) {
+        if (strncmp($node, $symbol, strlen($symbol)) === 0) {
+          if (!isset($hash_map[$symbol])) {
+            $hash_map[$symbol] = $node;
+          }
+        }
+      }
+    }
+
+    // Remove entries resulting in collisions, which set empty string values
+    $hash_map = array_filter($hash_map);
+
+    $results = array();
+    foreach ($symbol_map as $key => $symbol) {
+      if (isset($hash_map[$symbol])) {
+        $results[$key] = $hash_map[$symbol];
+      }
+    }
+
+    foreach ($results as $key => $result) {
+      if ($result === null) {
+        continue;
+      }
+
+      $ref = id(new ArcanistCommitRef())
+        ->setCommitHash($result);
+
+      $results[$key] = $ref;
+    }
+
+    yield $this->yieldMap($results);
+  }
+
+  private function validateSymbol($symbol) {
+    if (strpos($symbol, "\n") !== false) {
+      throw new Exception(
+        pht(
+          'Commit symbol "%s" contains a newline. This is not a valid '.
+          'character in a Mercurial commit symbol.',
+          addcslashes($symbol, "\\\n")));
+    }
+  }
+
+}

src/repository/api/ArcanistMercurialAPI.php

@@ -5,6 +5,13 @@
  */
 final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
 
+  /**
+   * Mercurial deceptively indicates that the default encoding is UTF-8 however
+   * however the actual default appears to be "something else", at least on
+   * Windows systems. Force all mercurial commands to use UTF-8 encoding.
+   */
+  const ROOT_HG_COMMAND = 'hg --encoding utf-8 ';
+
   private $branch;
   private $localCommitInfo;
   private $rawDiffCache = array();
@@ -13,25 +20,24 @@ final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
   private $featureFutures = array();
 
   protected function buildLocalFuture(array $argv) {
-    $env = $this->getMercurialEnvironmentVariables();
+    $argv[0] = self::ROOT_HG_COMMAND.$argv[0];
 
-    $argv[0] = 'hg '.$argv[0];
+    return $this->newConfiguredFuture(newv('ExecFuture', $argv));
-
-    $future = newv('ExecFuture', $argv)
-      ->setEnv($env)
-      ->setCWD($this->getPath());
-
-    return $future;
   }
 
   public function newPassthru($pattern /* , ... */) {
     $args = func_get_args();
+    $args[0] = self::ROOT_HG_COMMAND.$args[0];
+
+    return $this->newConfiguredFuture(newv('PhutilExecPassthru', $args));
+  }
+
+  private function newConfiguredFuture(PhutilExecutableFuture $future) {
+    $args = func_get_args();
 
     $env = $this->getMercurialEnvironmentVariables();
 
-    $args[0] = 'hg '.$args[0];
+    return $future
-
-    return newv('PhutilExecPassthru', $args)
       ->setEnv($env)
       ->setCWD($this->getPath());
   }
@@ -448,6 +454,10 @@ final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
     }
   }
 
+  protected function newCurrentCommitSymbol() {
+    return $this->getWorkingCopyRevision();
+  }
+
   public function getWorkingCopyRevision() {
     return '.';
   }
@@ -655,37 +665,117 @@ final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
   public function doCommit($message) {
     $tmp_file = new TempFile();
     Filesystem::writeFile($tmp_file, $message);
-    $this->execxLocal('commit -l %s', $tmp_file);
+    $this->execxLocal('commit --logfile %s', $tmp_file);
     $this->reloadWorkingCopy();
   }
 
   public function amendCommit($message = null) {
-    if ($message === null) {
+    $path_statuses = $this->buildUncommittedStatus();
+
+    $existing_message = $this->getCommitMessage(
+      $this->getWorkingCopyRevision());
+
+    if ($message === null || $message == $existing_message) {
+      if (empty($path_statuses)) {
+        // If there are no changes to the working directory and the message is
+        // not being changed then there's nothing to amend. Notably Mercurial
+        // will return an error code if trying to amend a commit with no change
+        // to the commit metadata or file changes.
+        return;
+      }
+
       $message = $this->getCommitMessage('.');
     }
 
     $tmp_file = new TempFile();
     Filesystem::writeFile($tmp_file, $message);
 
+    if ($this->getMercurialFeature('evolve')) {
+      $this->execxLocal('amend --logfile %s --', $tmp_file);
       try {
-      $this->execxLocal(
+        $this->execxLocal('evolve --all --');
-        'commit --amend -l %s',
-        $tmp_file);
       } catch (CommandException $ex) {
-      if (preg_match('/nothing changed/', $ex->getStdout())) {
+        $this->execxLocal('evolve --abort --');
-        // NOTE: Mercurial considers it an error to make a no-op amend. Although
-        // we generally defer to the underlying VCS to dictate behavior, this
-        // one seems a little goofy, and we use amend as part of various
-        // workflows under the assumption that no-op amends are fine. If this
-        // amend failed because it's a no-op, just continue.
-      } else {
         throw $ex;
       }
+      $this->reloadWorkingCopy();
+      return;
+    }
+
+    // Get the child nodes of the current changeset.
+    list($children) = $this->execxLocal(
+      'log --template %s --rev %s --',
+      '{node} ',
+      'children(.)');
+    $child_nodes = array_filter(explode(' ', $children));
+
+    // For a head commit we can simply use `commit --amend` for both new commit
+    // message and amending changes from the working directory.
+    if (empty($child_nodes)) {
+        $this->execxLocal('commit --amend --logfile %s --', $tmp_file);
+    } else {
+      $this->amendNonHeadCommit($child_nodes, $tmp_file);
     }
 
     $this->reloadWorkingCopy();
   }
 
+  /**
+   * Amends a non-head commit with a new message and file changes. This
+   * strategy is for Mercurial repositories without the evolve extension.
+   *
+   * 1. Run 'arc-amend' which uses Mercurial internals to amend the current
+   *    commit with updated message/file-changes. It results in a new commit
+   *    from the right parent
+   * 2. For each branch from the original commit, rebase onto the new commit,
+   *    removing the original branch. Note that there is potential for this to
+   *    cause a conflict but this is something the user has to address.
+   * 3. Strip the original commit.
+   *
+   * @param array     The list of child changesets off the original commit.
+   * @param file      The file containing the new commit message.
+   */
+  private function amendNonHeadCommit($child_nodes, $tmp_file) {
+    list($current) = $this->execxLocal(
+      'log --template %s --rev . --',
+      '{node}');
+
+    $this->execxLocalWithExtension(
+      'arc-hg',
+      'arc-amend --logfile %s',
+      $tmp_file);
+
+    list($new_commit) = $this->execxLocal(
+      'log --rev tip --template %s --',
+      '{node}');
+
+    try {
+      $rebase_args = array(
+        '--dest',
+        $new_commit,
+      );
+      foreach ($child_nodes as $child) {
+        $rebase_args[] = '--source';
+        $rebase_args[] = $child;
+      }
+
+      $this->execxLocalWithExtension(
+        'rebase',
+        'rebase %Ls --',
+        $rebase_args);
+    } catch (CommandException $ex) {
+      $this->execxLocalWithExtension(
+        'rebase',
+        'rebase --abort --');
+      throw $ex;
+    }
+
+    $this->execxLocalWithExtension(
+      'strip',
+      'strip --rev %s --',
+      $current);
+  }
+
   public function getCommitSummary($commit) {
     if ($commit == 'null') {
       return pht('(The Empty Void)');
@@ -957,6 +1047,129 @@ final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
     return $this->executeMercurialFeatureTest($feature, true);
   }
 
+  /**
+   * Returns the necessary flag for using a Mercurial extension. This will
+   * enable Mercurial built-in extensions and the "arc-hg" extension that is
+   * included with Arcanist. This will not enable other extensions, e.g.
+   * "evolve".
+   *
+   * @param string  The name of the extension to enable.
+   * @return string  A new command pattern that includes the necessary flags to
+   *                 enable the specified extension.
+   */
+  private function getMercurialExtensionFlag($extension) {
+    switch ($extension) {
+      case 'arc-hg':
+        $path = phutil_get_library_root('arcanist');
+        $path = dirname($path);
+        $path = $path.'/support/hg/arc-hg.py';
+        $ext_config = 'extensions.arc-hg='.$path;
+        break;
+      case 'rebase':
+        $ext_config = 'extensions.rebase=';
+        break;
+      case 'shelve':
+        $ext_config = 'extensions.shelve=';
+        break;
+      case 'strip':
+        $ext_config = 'extensions.strip=';
+        break;
+      default:
+        throw new Exception(
+          pht('Unknown Mercurial Extension: "%s".', $extension));
+    }
+
+    return csprintf('--config %s', $ext_config);
+  }
+
+  /**
+   * Produces the arguments that should be passed to Mercurial command
+   * execution that enables a desired extension.
+   *
+   * @param string  The name of the extension to enable.
+   * @param string  The command pattern that will be run with the extension
+   *                enabled.
+   * @param array   Parameters for the command pattern argument.
+   * @return array  An array where the first item is a Mercurial command
+   *                pattern that includes the necessary flag for enabling the
+   *                desired extension, and all remaining items are parameters
+   *                to that command pattern.
+   */
+  private function buildMercurialExtensionCommand(
+    $extension,
+    $pattern /* , ... */) {
+
+    $args = func_get_args();
+
+    $pattern_args = array_slice($args, 2);
+
+    $ext_flag = $this->getMercurialExtensionFlag($extension);
+
+    $full_cmd = $ext_flag.' '.$pattern;
+
+    $args = array_merge(
+      array($full_cmd),
+      $pattern_args);
+
+    return $args;
+  }
+
+  public function execxLocalWithExtension(
+    $extension,
+    $pattern /* , ... */) {
+
+    $args = func_get_args();
+    $extended_args = call_user_func_array(
+      array($this, 'buildMercurialExtensionCommand'),
+      $args);
+
+    return call_user_func_array(
+      array($this, 'execxLocal'),
+      $extended_args);
+  }
+
+  public function execFutureLocalWithExtension(
+    $extension,
+    $pattern /* , ... */) {
+
+    $args = func_get_args();
+    $extended_args = call_user_func_array(
+      array($this, 'buildMercurialExtensionCommand'),
+      $args);
+
+    return call_user_func_array(
+      array($this, 'execFutureLocal'),
+      $extended_args);
+  }
+
+  public function execPassthruWithExtension(
+    $extension,
+    $pattern /* , ... */) {
+
+    $args = func_get_args();
+    $extended_args = call_user_func_array(
+      array($this, 'buildMercurialExtensionCommand'),
+      $args);
+
+    return call_user_func_array(
+      array($this, 'execPassthru'),
+      $extended_args);
+  }
+
+  public function execManualLocalWithExtension(
+    $extension,
+    $pattern /* , ... */) {
+
+    $args = func_get_args();
+    $extended_args = call_user_func_array(
+      array($this, 'buildMercurialExtensionCommand'),
+      $args);
+
+    return call_user_func_array(
+      array($this, 'execManualLocal'),
+      $extended_args);
+  }
+
   private function executeMercurialFeatureTest($feature, $resolve) {
     if (array_key_exists($feature, $this->featureResults)) {
       return $this->featureResults[$feature];
@@ -982,8 +1195,9 @@ final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
   private function newMercurialFeatureFuture($feature) {
     switch ($feature) {
       case 'shelve':
-        return $this->execFutureLocal(
+        return $this->execFutureLocalWithExtension(
-          '--config extensions.shelve= shelve --help --');
+          'shelve',
+          'shelve --help --');
       case 'evolve':
         return $this->execFutureLocal('prune --help --');
       default:
@@ -1017,17 +1231,6 @@ final class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
     return new ArcanistMercurialRepositoryRemoteQuery();
   }
 
-  public function getMercurialExtensionArguments() {
-    $path = phutil_get_library_root('arcanist');
-    $path = dirname($path);
-    $path = $path.'/support/hg/arc-hg.py';
-
-    return array(
-      '--config',
-      'extensions.arc-hg='.$path,
-    );
-  }
-
   protected function newNormalizedURI($uri) {
     return new ArcanistRepositoryURINormalizer(
       ArcanistRepositoryURINormalizer::TYPE_MERCURIAL,

src/repository/marker/ArcanistMercurialRepositoryMarkerQuery.php

@@ -19,12 +19,6 @@ final class ArcanistMercurialRepositoryMarkerQuery
     // to provide a command which works like "git for-each-ref" locally and
     // "git ls-remote" when given a remote.
 
-    $argv = array();
-    foreach ($api->getMercurialExtensionArguments() as $arg) {
-      $argv[] = $arg;
-    }
-    $argv[] = 'arc-ls-markers';
-
     // NOTE: In remote mode, we're using passthru and a tempfile on this
     // because it's a remote command and may prompt the user to provide
     // credentials interactively. In local mode, we can just read stdout.
@@ -33,20 +27,17 @@ final class ArcanistMercurialRepositoryMarkerQuery
       $tmpfile = new TempFile();
       Filesystem::remove($tmpfile);
 
+      $argv = array();
       $argv[] = '--output';
       $argv[] = phutil_string_cast($tmpfile);
-    }
-
       $argv[] = '--';
-
-    if ($remote !== null) {
       $argv[] = $remote->getRemoteName();
-    }
 
-    if ($remote !== null) {
+      $err = $api->execPassthruWithExtension(
-      $passthru = $api->newPassthru('%Ls', $argv);
+        'arc-hg',
+        'arc-ls-markers %Ls',
+        $argv);
 
-      $err = $passthru->execute();
       if ($err) {
         throw new Exception(
           pht(
@@ -57,8 +48,10 @@ final class ArcanistMercurialRepositoryMarkerQuery
       $raw_data = Filesystem::readFile($tmpfile);
       unset($tmpfile);
     } else {
-      $future = $api->newFuture('%Ls', $argv);
+      $future = $api->execFutureLocalWithExtension(
-      list($raw_data) = $future->resolve();
+        'arc-hg',
+        'arc-ls-markers --');
+      list($err, $raw_data) = $future->resolve();
     }
 
     $items = phutil_json_decode($raw_data);

src/repository/marker/ArcanistRepositoryMarkerQuery.php

@@ -64,9 +64,11 @@ abstract class ArcanistRepositoryMarkerQuery
       $marker->attachWorkingCopyStateRef($state_ref);
 
       $hash = $marker->getCommitHash();
+      if ($hash !== null) {
         $hash = $api->getDisplayHash($hash);
         $marker->setDisplayHash($hash);
       }
+    }
 
     $types = $this->markerTypes;
     if ($types !== null) {

src/repository/state/ArcanistMercurialLocalState.php

@@ -7,6 +7,14 @@ final class ArcanistMercurialLocalState
   private $localBranch;
   private $localBookmark;
 
+  public function getLocalCommit() {
+    return $this->localCommit;
+  }
+
+  public function getLocalBookmark() {
+    return $this->localBookmark;
+  }
+
   protected function executeSaveLocalState() {
     $api = $this->getRepositoryAPI();
     $log = $this->getWorkflow()->getLogEngine();
@@ -152,8 +160,9 @@ final class ArcanistMercurialLocalState
       'arc-%s',
       Filesystem::readRandomCharacters(12));
 
-    $api->execxLocal(
+    $api->execxLocalWithExtension(
-      '--config extensions.shelve= shelve --unknown --name %s --',
+      'shelve',
+      'shelve --unknown --name %s --',
       $stash_ref);
 
     $log->writeStatus(
@@ -171,16 +180,18 @@ final class ArcanistMercurialLocalState
       pht('UNSHELVE'),
       pht('Restoring uncommitted changes to working copy.'));
 
-    $api->execxLocal(
+    $api->execxLocalWithExtension(
-      '--config extensions.shelve= unshelve --keep --name %s --',
+      'shelve',
+      'unshelve --keep --name %s --',
       $stash_ref);
   }
 
   protected function discardStash($stash_ref) {
     $api = $this->getRepositoryAPI();
 
-    $api->execxLocal(
+    $api->execxLocalWithExtension(
-      '--config extensions.shelve= shelve --delete %s --',
+      'shelve',
+      'shelve --delete %s --',
       $stash_ref);
   }
 

src/repository/state/ArcanistRepositoryLocalState.php

@@ -192,10 +192,28 @@ abstract class ArcanistRepositoryLocalState
     return false;
   }
 
+  /**
+   * Stash uncommitted changes temporarily. Use {@method:restoreStash()} to
+   * bring these changes back.
+   *
+   * Note that saving and restoring changes may not behave as expected if used
+   * in a non-stack manner, i.e. proper use involves only restoring stashes in
+   * the reverse order they were saved.
+   *
+   * @return wild  A reference object that refers to the changes which were
+   *               saved. When restoring changes this should be passed to
+   *               {@method:restoreStash()}.
+   */
   protected function saveStash() {
     throw new PhutilMethodNotImplementedException();
   }
 
+  /**
+   * Restores changes that were previously stashed by {@method:saveStash()}.
+   *
+   * @param wild  A reference object referring to which previously stashed
+   *              changes to restore, from invoking {@method:saveStash()}.
+   */
   protected function restoreStash($ref) {
     throw new PhutilMethodNotImplementedException();
   }

src/runtime/ArcanistRuntime.php

@@ -270,9 +270,9 @@ final class ArcanistRuntime {
         $problems[] = sprintf(
           'The build of PHP you are running was compiled with the configure '.
           'flag "%s", which means it does not support the function "%s()". '.
-          'This function is required for Arcanist to run. Install a standard '.
+          'This function is required for this software to run. Install a '.
-          'build of PHP or rebuild it without this flag. You may also be '.
+          'standard build of PHP or rebuild it without this flag. You may '.
-          'able to build or install the relevant extension separately.',
+          'also be able to build or install the relevant extension separately.',
           $which,
           $fname);
         continue;
@@ -477,8 +477,8 @@ final class ArcanistRuntime {
       $log->writeWarn(
         pht('VERY META'),
         pht(
-          'You are running one copy of Arcanist (at path "%s") against '.
+          'You are running one copy of this software (at path "%s") against '.
-          'another copy of Arcanist (at path "%s"). Code in the current '.
+          'another copy of this software (at path "%s"). Code in the current '.
           'working directory will not be loaded or executed.',
           $executing_directory,
           $working_directory));
@@ -519,10 +519,10 @@ final class ArcanistRuntime {
     if (!isset($toolsets[$binary])) {
       throw new PhutilArgumentUsageException(
         pht(
-          'Arcanist toolset "%s" is unknown. The Arcanist binary should '.
+          'Toolset "%s" is unknown. The binary should be executed so that '.
-          'be executed so that "argv[0]" identifies a supported toolset. '.
+          '"argv[0]" identifies a supported toolset. Rename the binary or '.
-          'Rename the binary or install the library that provides the '.
+          'install the library that provides the desired toolset. Current '.
-          'desired toolset. Current available toolsets: %s.',
+          'available toolsets: %s.',
           $binary,
           implode(', ', array_keys($toolsets))));
     }

src/serviceprofiler/PhutilServiceProfiler.php

@@ -137,7 +137,7 @@ final class PhutilServiceProfiler extends Phobject {
 
           $uri = phutil_censor_credentials($data['uri']);
 
-          if (strlen($proxy)) {
+          if ($proxy !== null) {
             $desc = "{$proxy} >> {$uri}";
           } else {
             $desc = $uri;
@@ -203,6 +203,10 @@ final class PhutilServiceProfiler extends Phobject {
   }
 
   private static function escapeProfilerStringForDisplay($string) {
+    if ($string === null) {
+      return '';
+    }
+
     // Convert tabs and newlines to spaces and collapse blocks of whitespace,
     // most often formatting in queries.
     $string = preg_replace('/\s{2,}/', ' ', $string);

src/symbols/PhutilClassMapQuery.php

@@ -226,8 +226,8 @@ final class PhutilClassMapQuery extends Phobject {
     $unique = $this->uniqueMethod;
     $sort = $this->sortMethod;
 
-    if (strlen($expand)) {
+    if ($expand !== null) {
-      if (!strlen($unique)) {
+      if ($unique === null) {
         throw new Exception(
           pht(
             'Trying to execute a class map query for descendants of class '.
@@ -245,7 +245,7 @@ final class PhutilClassMapQuery extends Phobject {
       ->loadObjects();
 
     // Apply the "expand" mechanism, if it is configured.
-    if (strlen($expand)) {
+    if ($expand !== null) {
       $list = array();
       foreach ($objects as $object) {
         foreach (call_user_func(array($object, $expand)) as $instance) {
@@ -257,7 +257,7 @@ final class PhutilClassMapQuery extends Phobject {
     }
 
     // Apply the "unique" mechanism, if it is configured.
-    if (strlen($unique)) {
+    if ($unique !== null) {
       $map = array();
       foreach ($list as $object) {
         $key = call_user_func(array($object, $unique));
@@ -287,12 +287,12 @@ final class PhutilClassMapQuery extends Phobject {
     }
 
     // Apply the "filter" mechanism, if it is configured.
-    if (strlen($filter)) {
+    if ($filter !== null) {
       $map = mfilter($map, $filter);
     }
 
     // Apply the "sort" mechanism, if it is configured.
-    if (strlen($sort)) {
+    if ($sort !== null) {
       if ($map) {
         // The "sort" method may return scalars (which we want to sort with
         // "msort()"), or may return PhutilSortVector objects (which we want

src/symbols/PhutilSymbolLoader.php

@@ -296,11 +296,12 @@ final class PhutilSymbolLoader {
         // library without breaking library startup.
         if ($should_continue) {
           // We may not have `pht()` yet.
-          fprintf(
+          $message = sprintf(
-            STDERR,
             "%s: %s\n",
             'IGNORING CLASS LOAD FAILURE',
             $caught->getMessage());
+
+          @file_put_contents('php://stderr', $message);
         } else {
           throw $caught;
         }

src/toolset/ArcanistArcToolset.php

@@ -9,7 +9,7 @@ final class ArcanistArcToolset extends ArcanistToolset {
       array(
         'name' => 'conduit-uri',
         'param' => 'uri',
-        'help' => pht('Connect to Phabricator install specified by __uri__.'),
+        'help' => pht('Connect to server specified by __uri__.'),
       ),
       array(
         'name' => 'conduit-token',

src/toolset/workflow/ArcanistShellCompleteWorkflow.php

@@ -14,7 +14,7 @@ final class ArcanistShellCompleteWorkflow
   public function getWorkflowInformation() {
     $help = pht(<<<EOTEXT
 Install shell completion so you can use the "tab" key to autocomplete
-commands and flags in your shell for Arcanist toolsets and workflows.
+commands and flags in your shell for toolsets and workflows.
 
 The **bash** shell is supported.
 
@@ -28,7 +28,7 @@ This will install shell completion into your current shell. After installing,
 you may need to start a new shell (or open a new terminal window) to pick up
 the updated configuration.
 
-Once installed, completion should work across all Arcanist toolsets.
+Once installed, completion should work across all toolsets.
 
 **Using Completion**
 
@@ -53,9 +53,9 @@ You can update shell completion without reinstalling it by running:
 
 You may need to update shell completion if:
 
-  - you install new Arcanist toolsets; or
+  - you install new toolsets; or
-  - you move the Arcanist directory; or
+  - you move this software on disk; or
-  - you upgrade Arcanist and the new version fixes shell completion bugs.
+  - you upgrade this software and the new version fixes shell completion bugs.
 EOTEXT
 );
 

src/unit/engine/PhutilUnitTestEngine.php

@@ -170,16 +170,14 @@ final class PhutilUnitTestEngine extends ArcanistUnitTestEngine {
       if (!$library_name) {
         throw new Exception(
           pht(
-            "Attempting to run unit tests on a libphutil library which has ".
+            "Attempting to run unit tests on a library which has ".
             "not been loaded, at:\n\n".
             "    %s\n\n".
-            "This probably means one of two things:\n\n".
+            "Make sure this library is configured to load.\n\n".
-            "    - You may need to add this library to %s.\n".
+            "(In rare cases, this may be because you are attempting to run ".
-            "    - You may be running tests on a copy of libphutil or ".
+            "one copy of this software against a different copy of this ".
-            "arcanist using a different copy of libphutil or arcanist. ".
+            "software. This operation is not supported.)",
-            "This operation is not supported.\n",
+            $library_root));
-            $library_root,
-            '.arcconfig.'));
       }
 
       $path = Filesystem::resolvePath($path, $root);

src/unit/engine/phutil/PhutilTestCase.php

@@ -154,6 +154,147 @@ abstract class PhutilTestCase extends Phobject {
     throw new PhutilTestSkippedException($message);
   }
 
+  final protected function assertCaught(
+    $expect,
+    $actual,
+    $message = null) {
+
+    if ($message !== null) {
+      $message = phutil_string_cast($message);
+    }
+
+    if ($actual === null) {
+      // This is okay: no exception.
+    } else if ($actual instanceof Exception) {
+      // This is also okay.
+    } else if ($actual instanceof Throwable) {
+      // And this is okay too.
+    } else {
+      // Anything else is no good.
+
+      if ($message !== null) {
+        $output = pht(
+          'Call to "assertCaught(..., <junk>, ...)" for test case "%s" '.
+          'passed bad value for test result. Expected null, Exception, '.
+          'or Throwable; got: %s.',
+          $message,
+          phutil_describe_type($actual));
+      } else {
+        $output = pht(
+          'Call to "assertCaught(..., <junk>, ...)" passed bad value for '.
+          'test result. Expected null, Exception, or Throwable; got: %s.',
+          phutil_describe_type($actual));
+      }
+
+      $this->failTest($output);
+
+      throw new PhutilTestTerminatedException($output);
+    }
+
+    $expect_list = null;
+
+    if ($expect === false) {
+      $expect_list = array();
+    } else if ($expect === true) {
+      $expect_list = array(
+        'Exception',
+        'Throwable',
+      );
+    } else if (is_string($expect) || is_array($expect)) {
+      $list = (array)$expect;
+
+      $items_ok = true;
+      foreach ($list as $key => $item) {
+        if (!phutil_nonempty_stringlike($item)) {
+          $items_ok = false;
+          break;
+        }
+
+        $list[$key] = phutil_string_cast($item);
+      }
+
+      if ($items_ok) {
+        $expect_list = $list;
+      }
+    }
+
+    if ($expect_list === null) {
+      if ($message !== null) {
+        $output = pht(
+          'Call to "assertCaught(<junk>, ...)" for test case "%s" '.
+          'passed bad expected value. Expected bool, class name as a string, '.
+          'or a list of class names. Got: %s.',
+          $message,
+          phutil_describe_type($expect));
+      } else {
+        $output = pht(
+          'Call to "assertCaught(<junk>, ...)" passed bad expected value. '.
+          'expected result. Expected null, Exception, or Throwable; got: %s.',
+          phutil_describe_type($expect));
+      }
+
+      $this->failTest($output);
+
+      throw new PhutilTestTerminatedException($output);
+    }
+
+    if ($actual === null) {
+      $is_match = !$expect_list;
+    } else {
+      $is_match = false;
+      foreach ($expect_list as $exception_class) {
+        if ($actual instanceof $exception_class) {
+          $is_match = true;
+          break;
+        }
+      }
+    }
+
+    if ($is_match) {
+      $this->assertions++;
+      return;
+    }
+
+    $caller = self::getCallerInfo();
+    $file = $caller['file'];
+    $line = $caller['line'];
+
+    $output = array();
+
+    if ($message !== null) {
+      $output[] = pht(
+        'Assertion of caught exception failed (at %s:%d in test case "%s").',
+        $file,
+        $line,
+        $message);
+    } else {
+      $output[] = pht(
+        'Assertion of caught exception failed (at %s:%d).',
+        $file,
+        $line);
+    }
+
+    if ($actual === null) {
+      $output[] = pht('Expected any exception, got no exception.');
+    } else if (!$expect_list) {
+      $output[] = pht(
+        'Expected no exception, got exception of class "%s".',
+        get_class($actual));
+    } else {
+      $expected_classes = implode(', ', $expect_list);
+      $output[] = pht(
+        'Expected exception (in class(es): %s), got exception of class "%s".',
+        $expected_classes,
+        get_class($actual));
+    }
+
+    $output = implode("\n\n", $output);
+
+    $this->failTest($output);
+
+    throw new PhutilTestTerminatedException($output);
+  }
+
 
 /* -(  Exception Handling  )------------------------------------------------- */
 

src/unit/renderer/ArcanistUnitConsoleRenderer.php

@@ -65,9 +65,10 @@ final class ArcanistUnitConsoleRenderer extends ArcanistUnitRenderer {
       50   => "<fg:green>%s</fg><fg:yellow>{$star}</fg> ",
       200  => '<fg:green>%s</fg>  ',
       500  => '<fg:yellow>%s</fg>  ',
-      INF  => '<fg:red>%s</fg>  ',
     );
 
+    $least_acceptable = '<fg:red>%s</fg>  ';
+
     $milliseconds = $seconds * 1000;
     $duration = $this->formatTime($seconds);
     foreach ($acceptableness as $upper_bound => $formatting) {
@@ -75,7 +76,8 @@ final class ArcanistUnitConsoleRenderer extends ArcanistUnitRenderer {
         return phutil_console_format($formatting, $duration);
       }
     }
-    return phutil_console_format(end($acceptableness), $duration);
+
+    return phutil_console_format($least_acceptable, $duration);
   }
 
   private function formatTime($seconds) {

src/upload/ArcanistFileUploader.php

@@ -313,7 +313,7 @@ final class ArcanistFileUploader extends Phobject {
    * @task internal
    */
   private function writeStatus($message) {
-    fwrite(STDERR, $message."\n");
+    PhutilSystem::writeStderr($message."\n");
   }
 
 }

src/utils/PhutilArray.php

@@ -29,6 +29,7 @@ abstract class PhutilArray
 /* -(  Countable Interface  )------------------------------------------------ */
 
 
+  #[\ReturnTypeWillChange]
   public function count() {
     return count($this->data);
   }
@@ -37,22 +38,27 @@ abstract class PhutilArray
 /* -(  Iterator Interface  )------------------------------------------------- */
 
 
+  #[\ReturnTypeWillChange]
   public function current() {
     return current($this->data);
   }
 
+  #[\ReturnTypeWillChange]
   public function key() {
     return key($this->data);
   }
 
+  #[\ReturnTypeWillChange]
   public function next() {
     return next($this->data);
   }
 
+  #[\ReturnTypeWillChange]
   public function rewind() {
     reset($this->data);
   }
 
+  #[\ReturnTypeWillChange]
   public function valid() {
     return (key($this->data) !== null);
   }
@@ -61,18 +67,22 @@ abstract class PhutilArray
 /* -(  ArrayAccess Interface  )---------------------------------------------- */
 
 
+  #[\ReturnTypeWillChange]
   public function offsetExists($key) {
     return array_key_exists($key, $this->data);
   }
 
+  #[\ReturnTypeWillChange]
   public function offsetGet($key) {
     return $this->data[$key];
   }
 
+  #[\ReturnTypeWillChange]
   public function offsetSet($key, $value) {
     $this->data[$key] = $value;
   }
 
+  #[\ReturnTypeWillChange]
   public function offsetUnset($key) {
     unset($this->data[$key]);
   }

src/utils/PhutilCallbackFilterIterator.php

@@ -18,6 +18,7 @@ final class PhutilCallbackFilterIterator extends FilterIterator {
     $this->callback = $callback;
   }
 
+  #[\ReturnTypeWillChange]
   public function accept() {
     return call_user_func($this->callback, $this->current());
   }

src/utils/PhutilSystem.php

@@ -3,10 +3,73 @@
 /**
  * Interact with the operating system.
  *
+ * @task stdio Interacting with Standard I/O
  * @task memory Interacting with System Memory
  */
 final class PhutilSystem extends Phobject {
 
+  private static $stdin = false;
+  private static $stderr = false;
+  private static $stdout = false;
+
+  /**
+   * @task stdio
+   */
+  public static function getStdinHandle() {
+    if (self::$stdin === false) {
+      self::$stdin = self::getStdioHandle('STDIN');
+    }
+
+    return self::$stdin;
+  }
+
+  /**
+   * @task stdio
+   */
+  public static function getStdoutHandle() {
+    if (self::$stdout === false) {
+      self::$stdout = self::getStdioHandle('STDOUT');
+    }
+
+    return self::$stdout;
+  }
+
+  /**
+   * @task stdio
+   */
+  public static function getStderrHandle() {
+    if (self::$stderr === false) {
+      self::$stderr = self::getStdioHandle('STDERR');
+    }
+
+    return self::$stderr;
+  }
+
+  /**
+   * @task stdio
+   */
+  public static function writeStderr($message) {
+    $stderr = self::getStderrHandle();
+
+    if ($stderr === null) {
+      return;
+    }
+
+    $message = phutil_string_cast($message);
+    @fwrite($stderr, $message);
+  }
+
+
+  /**
+   * @task stdio
+   */
+  private static function getStdioHandle($ref) {
+    if (defined($ref)) {
+      return constant($ref);
+    }
+
+    return null;
+  }
 
   /**
    * Get information about total and free memory on the system.

src/utils/__tests__/PhutilUtilsTestCase.php

@@ -1000,4 +1000,74 @@ final class PhutilUtilsTestCase extends PhutilTestCase {
     }
   }
 
+  public function testEmptyStringMethods() {
+
+    $uri = new PhutilURI('http://example.org/');
+
+    $map = array(
+      array(null, false, false, false, 'literal null'),
+      array('', false, false, false, 'empty string'),
+      array('x', true, true, true, 'nonempty string'),
+      array(false, null, null, null, 'bool'),
+      array(1, null, null, true, 'integer'),
+      array($uri, null, true, true, 'uri object'),
+      array(2.5, null, null, true, 'float'),
+      array(array(), null, null, null, 'array'),
+      array((object)array(), null, null, null, 'object'),
+    );
+
+    foreach ($map as $test_case) {
+      $input = $test_case[0];
+
+      $expect_string = $test_case[1];
+      $expect_stringlike = $test_case[2];
+      $expect_scalar = $test_case[3];
+
+      $test_name = $test_case[4];
+
+      $this->executeEmptyStringTest(
+        $input,
+        $expect_string,
+        'phutil_nonempty_string',
+        $test_name);
+
+      $this->executeEmptyStringTest(
+        $input,
+        $expect_stringlike,
+        'phutil_nonempty_stringlike',
+        $test_name);
+
+      $this->executeEmptyStringTest(
+        $input,
+        $expect_scalar,
+        'phutil_nonempty_scalar',
+        $test_name);
+    }
+
+  }
+
+  private function executeEmptyStringTest($input, $expect, $call, $name) {
+    $name = sprintf('%s(<%s>)', $call, $name);
+
+    $caught = null;
+    try {
+      $actual = call_user_func($call, $input);
+    } catch (Exception $ex) {
+      $caught = $ex;
+    } catch (Throwable $ex) {
+      $caught = $ex;
+    }
+
+    if ($expect === null) {
+      $expect_exceptions = array('InvalidArgumentException');
+    } else {
+      $expect_exceptions = false;
+    }
+
+    $this->assertCaught($expect_exceptions, $caught, $name);
+    if (!$caught) {
+      $this->assertEqual($expect, $actual, $name);
+    }
+  }
+
 }

src/utils/utf8.php

@@ -314,6 +314,8 @@ function phutil_utf8_strlen($string) {
  * @return  int     The console display length of the string.
  */
 function phutil_utf8_console_strlen($string) {
+  $string = phutil_string_cast($string);
+
   // Formatting and colors don't contribute any width in the console.
   $string = preg_replace("/\x1B\[\d*m/", '', $string);
 

src/utils/utils.php

@@ -2094,3 +2094,128 @@ function phutil_raise_preg_exception($function, array $argv) {
 
   throw new PhutilRegexException($message);
 }
+
+
+/**
+ * Test if a value is a nonempty string.
+ *
+ * The value "null" and the empty string are considered empty; all other
+ * strings are considered nonempty.
+ *
+ * This method raises an exception if passed a value which is neither null
+ * nor a string.
+ *
+ * @param Value to test.
+ * @return bool True if the parameter is a nonempty string.
+ */
+function phutil_nonempty_string($value) {
+  if ($value === null) {
+    return false;
+  }
+
+  if ($value === '') {
+    return false;
+  }
+
+  if (is_string($value)) {
+    return true;
+  }
+
+  throw new InvalidArgumentException(
+    pht(
+      'Call to phutil_nonempty_string() expected null or a string, got: %s.',
+      phutil_describe_type($value)));
+}
+
+
+/**
+ * Test if a value is a nonempty, stringlike value.
+ *
+ * The value "null", the empty string, and objects which have a "__toString()"
+ * method which returns the empty string are empty.
+ *
+ * Other strings, and objects with a "__toString()" method that returns a
+ * string other than the empty string are considered nonempty.
+ *
+ * This method raises an exception if passed any other value.
+ *
+ * @param Value to test.
+ * @return bool True if the parameter is a nonempty, stringlike value.
+ */
+function phutil_nonempty_stringlike($value) {
+  if ($value === null) {
+    return false;
+  }
+
+  if ($value === '') {
+    return false;
+  }
+
+  if (is_string($value)) {
+    return true;
+  }
+
+  if (is_object($value)) {
+    try {
+      $string = phutil_string_cast($value);
+      return phutil_nonempty_string($string);
+    } catch (Exception $ex) {
+      // Continue below.
+    } catch (Throwable $ex) {
+      // Continue below.
+    }
+  }
+
+  throw new InvalidArgumentException(
+    pht(
+      'Call to phutil_nonempty_stringlike() expected a string or stringlike '.
+      'object, got: %s.',
+      phutil_describe_type($value)));
+}
+
+
+/**
+ * Test if a value is a nonempty, scalar value.
+ *
+ * The value "null", the empty string, and objects which have a "__toString()"
+ * method which returns the empty string are empty.
+ *
+ * Other strings, objects with a "__toString()" method which returns a
+ * string other than the empty string, integers, and floats are considered
+ * scalar.
+ *
+ * This method raises an exception if passed any other value.
+ *
+ * @param Value to test.
+ * @return bool True if the parameter is a nonempty, scalar value.
+ */
+function phutil_nonempty_scalar($value) {
+  if ($value === null) {
+    return false;
+  }
+
+  if ($value === '') {
+    return false;
+  }
+
+  if (is_string($value) || is_int($value) || is_float($value)) {
+    return true;
+  }
+
+  if (is_object($value)) {
+    try {
+      $string = phutil_string_cast($value);
+      return phutil_nonempty_string($string);
+    } catch (Exception $ex) {
+      // Continue below.
+    } catch (Throwable $ex) {
+      // Continue below.
+    }
+  }
+
+  throw new InvalidArgumentException(
+    pht(
+      'Call to phutil_nonempty_scalar() expected: a string; or stringlike '.
+      'object; or int; or float. Got: %s.',
+      phutil_describe_type($value)));
+}

src/utils/viewutils.php

@@ -141,7 +141,7 @@ function phutil_format_units_generic(
   $scale = array_shift($scales);
   $label = array_shift($labels);
   while ($n >= $scale && count($labels)) {
-    $remainder += ($n % $scale) * $accum;
+    $remainder += ((int)$n % $scale) * $accum;
     $n /= $scale;
     $accum *= $scale;
     $label = array_shift($labels);

src/workflow/ArcanistAmendWorkflow.php

@@ -164,8 +164,6 @@ EOTEXT
         ->execute();
     }
 
-    return;
-
     if ($api->getUncommittedChanges()) {
       // TODO: Make this class of error show the uncommitted changes.
 

src/workflow/ArcanistCallConduitWorkflow.php

@@ -15,8 +15,7 @@ Allows you to make a raw Conduit method call:
   - Call parameters are required, and read as a JSON blob from stdin.
   - Results are written to stdout as a JSON blob.
 
-This workflow is primarily useful for writing scripts which integrate
+This workflow is primarily useful for writing scripts. Examples:
-with Phabricator. Examples:
 
   $ echo '{}' | arc call-conduit -- conduit.ping
   $ echo '{"phid":"PHID-FILE-xxxx"}' | arc call-conduit -- file.download

src/workflow/ArcanistDiffWorkflow.php

@@ -115,8 +115,7 @@ EOTEXT
       'raw' => array(
         'help' => pht(
           'Read diff from stdin, not from the working copy. This disables '.
-          'many Arcanist/Phabricator features which depend on having access '.
+          'many features which depend on having access to the working copy.'),
-          'to the working copy.'),
         'conflicts' => array(
           'apply-patches'       => pht('%s disables lint.', '--raw'),
           'never-apply-patches' => pht('%s disables lint.', '--raw'),
@@ -138,8 +137,8 @@ EOTEXT
         'param' => 'command',
         'help' => pht(
           'Generate diff by executing a specified command, not from the '.
-          'working copy. This disables many Arcanist/Phabricator features '.
+          'working copy. This disables many features which depend on having '.
-          'which depend on having access to the working copy.'),
+          'access to the working copy.'),
         'conflicts' => array(
           'apply-patches'       => pht('%s disables lint.', '--raw-command'),
           'never-apply-patches' => pht('%s disables lint.', '--raw-command'),
@@ -326,9 +325,8 @@ EOTEXT
       'head' => array(
         'param' => 'commit',
         'help' => pht(
-          'Specify the end of the commit range. This disables many '.
+          'Specify the end of the commit range. This disables many features '.
-          'Arcanist/Phabricator features which depend on having access to '.
+          'which depend on having access to the working copy.'),
-          'the working copy.'),
         'supports' => array('git'),
         'nosupport' => array(
           'svn' => pht('Subversion does not support commit ranges.'),
@@ -517,7 +515,7 @@ EOTEXT
           if ($is_draft) {
             throw new ArcanistUsageException(
               pht(
-                'You have specified "--draft", but the version of Phabricator '.
+                'You have specified "--draft", but the software version '.
                 'on the server is too old to support draft revisions. Omit '.
                 'the flag or upgrade the server software.'));
           }
@@ -674,6 +672,8 @@ EOTEXT
       if ($should_edit) {
         $edited = $this->newInteractiveEditor($remote_corpus)
           ->setName('differential-edit-revision-info')
+          ->setTaskMessage(pht(
+            'Update the details for a revision, then save and exit.'))
           ->editInteractively();
         if ($edited != $remote_corpus) {
           $remote_corpus = $edited;
@@ -699,7 +699,7 @@ EOTEXT
       $this->revisionID = $revision_id;
 
       $revision['message'] = $this->getArgument('message');
-      if (!strlen($revision['message'])) {
+      if ($revision['message'] === null) {
         $update_messages = $this->readScratchJSONFile('update-messages.json');
 
         $update_messages[$revision_id] = $this->getUpdateMessage(
@@ -806,7 +806,10 @@ EOTEXT
     if ($is_raw) {
 
       if ($this->getArgument('raw')) {
-        fwrite(STDERR, pht('Reading diff from stdin...')."\n");
+        PhutilSystem::writeStderr(
+          tsprintf(
+            "%s\n",
+            pht('Reading diff from stdin...')));
         $raw_diff = file_get_contents('php://stdin');
       } else if ($this->getArgument('raw-command')) {
         list($raw_diff) = execx('%C', $this->getArgument('raw-command'));
@@ -947,7 +950,7 @@ EOTEXT
             } catch (ConduitClientException $e) {
               if ($e->getErrorCode() == 'ERR-BAD-ARCANIST-PROJECT') {
                 echo phutil_console_wrap(
-                  pht('Lookup of encoding in arcanist project failed: %s',
+                  pht('Lookup of encoding in project failed: %s',
                       $e->getMessage())."\n");
               } else {
                 throw $e;
@@ -988,10 +991,10 @@ EOTEXT
             'these files will be marked as binary.',
             phutil_count($utf8_problems)),
           pht(
-            "You can learn more about how Phabricator handles character ".
+            "You can learn more about how this software handles character ".
             "encodings (and how to configure encoding settings and detect and ".
             "correct encoding problems) by reading 'User Guide: UTF-8 and ".
-            "Character Encoding' in the Phabricator documentation."),
+            "Character Encoding' in the documentation."),
           pht(
             '%s AFFECTED FILE(S)',
             phutil_count($utf8_problems)));
@@ -1476,6 +1479,8 @@ EOTEXT
       } else {
         $new_template = $this->newInteractiveEditor($template)
           ->setName('new-commit')
+          ->setTaskMessage(pht(
+            'Provide the details for a new revision, then save and exit.'))
           ->editInteractively();
       }
       $first = false;
@@ -1736,9 +1741,12 @@ EOTEXT
     if ($template == '') {
       $comments = $this->getDefaultUpdateMessage();
 
+      $comments = phutil_string_cast($comments);
+      $comments = rtrim($comments);
+
       $template = sprintf(
         "%s\n\n# %s\n#\n# %s\n# %s\n#\n# %s\n#  $ %s\n\n",
-        rtrim($comments),
+        $comments,
         pht(
           'Updating %s: %s',
           "D{$fields['revisionID']}",
@@ -1752,6 +1760,8 @@ EOTEXT
 
     $comments = $this->newInteractiveEditor($template)
       ->setName('differential-update-comments')
+      ->setTaskMessage(pht(
+        'Update the revision comments, then save and exit.'))
       ->editInteractively();
 
     return $comments;
@@ -2354,7 +2364,7 @@ EOTEXT
     if (strlen($branch)) {
       $upstream_path = $api->getPathToUpstream($branch);
       $remote_branch = $upstream_path->getRemoteBranchName();
-      if (strlen($remote_branch)) {
+      if ($remote_branch !== null) {
         return array(
           array(
             'type' => 'branch',
@@ -2368,7 +2378,7 @@ EOTEXT
     // If "arc.land.onto.default" is configured, use that.
     $config_key = 'arc.land.onto.default';
     $onto = $this->getConfigFromAnySource($config_key);
-    if (strlen($onto)) {
+    if ($onto !== null) {
       return array(
         array(
           'type' => 'branch',
@@ -2643,7 +2653,7 @@ EOTEXT
     if (!$supported) {
       $this->writeInfo(
         pht('SKIP STAGING'),
-        pht('Phabricator does not support staging areas for this repository.'));
+        pht('The server does not support staging areas for this repository.'));
       return self::STAGING_REPOSITORY_UNSUPPORTED;
     }
 

src/workflow/ArcanistInstallCertificateWorkflow.php

@@ -19,12 +19,12 @@ EOTEXT
   public function getCommandHelp() {
     return phutil_console_format(<<<EOTEXT
           Supports: http, https
-          Installs Conduit credentials into your ~/.arcrc for the given install
+          Installs Conduit credentials into your ~/.arcrc for the given server.
-          of Phabricator. You need to do this before you can use 'arc', as it
+          You need to do this before you can use 'arc', as it enables 'arc' to
-          enables 'arc' to link your command-line activity with your account on
+          link your command-line activity with your account on the web. Run
-          the web. Run this command from within a project directory to install
+          this command from within a project directory to install that
-          that project's certificate, or specify an explicit URI (like
+          project's certificate, or specify an explicit URI (like
-          "https://phabricator.example.com/").
+          "https://devtools.example.com/").
 EOTEXT
       );
   }
@@ -91,12 +91,11 @@ EOTEXT
       // Ignore.
     }
 
-    echo phutil_console_format("**%s**\n", pht('LOGIN TO PHABRICATOR'));
+    echo phutil_console_format("**%s**\n", pht('LOG IN'));
     echo phutil_console_format(
       "%s\n\n%s\n\n%s",
       pht(
-        'Open this page in your browser and login to '.
+        'Open this page in your browser and log in if necessary:'),
-        'Phabricator if necessary:'),
       $token_uri,
       pht('Then paste the API Token on that page below.'));
 
@@ -204,7 +203,7 @@ EOTEXT
       $uri = $conduit_uri;
     }
 
-    $example = 'https://phabricator.example.com/';
+    $example = 'https://devtools.example.com/';
 
     $uri_object = new PhutilURI($uri);
     $protocol = $uri_object->getProtocol();

src/workflow/ArcanistLiberateWorkflow.php

@@ -11,13 +11,13 @@ final class ArcanistLiberateWorkflow
     // TOOLSETS: Expand this help.
 
     $help = pht(<<<EOTEXT
-Create or update an Arcanist library.
+Create or update a library.
 EOTEXT
 );
 
     return $this->newWorkflowInformation()
       ->setSynopsis(
-        pht('Create or update an Arcanist library.'))
+        pht('Create or update a library.'))
       ->addExample(pht('**liberate**'))
       ->addExample(pht('**liberate** [__path__]'))
       ->setHelp($help);
@@ -79,22 +79,35 @@ EOTEXT
       );
     }
 
+    $any_errors = false;
     foreach ($paths as $path) {
       $log->writeStatus(
         pht('WORK'),
         pht(
           'Updating library: %s',
           Filesystem::readablePath($path).DIRECTORY_SEPARATOR));
-      $this->liberatePath($path);
+      $exit_code = $this->liberatePath($path);
+      if ($exit_code !== 0) {
+        $any_errors = true;
+        $log->writeError(
+          pht('ERROR'),
+          pht('Failed to update library: %s', $path));
+      }
     }
 
+    if (!$any_errors) {
       $log->writeSuccess(
         pht('DONE'),
         pht('Updated %s librarie(s).', phutil_count($paths)));
+    }
 
     return 0;
   }
 
+  /**
+   * @return  int The exit code of running the rebuild-map.php script, which
+   *              will be 0 to indicate success or non-zero for failure.
+   */
   private function liberatePath($path) {
     if (!Filesystem::pathExists($path.'/__phutil_library_init__.php')) {
       echo tsprintf(
@@ -103,8 +116,7 @@ EOTEXT
           'No library currently exists at the path "%s"...',
           $path));
       $this->liberateCreateDirectory($path);
-      $this->liberateCreateLibrary($path);
+      return $this->liberateCreateLibrary($path);
-      return;
     }
 
     $version = $this->getLibraryFormatVersion($path);
@@ -119,8 +131,6 @@ EOTEXT
         throw new ArcanistUsageException(
           pht("Unknown library version '%s'!", $version));
     }
-
-    echo tsprintf("%s\n", pht('Done.'));
   }
 
   private function getLibraryFormatVersion($path) {
@@ -140,6 +150,10 @@ EOTEXT
     return 1;
   }
 
+  /**
+   * @return  int The exit code of running the rebuild-map.php script, which
+   *              will be 0 to indicate success or non-zero for failure.
+   */
   private function liberateVersion2($path) {
     $bin = $this->getScriptPath('support/lib/rebuild-map.php');
 
@@ -181,10 +195,14 @@ EOTEXT
     execx('mkdir -p %R', $path);
   }
 
+  /**
+   * @return  int The exit code of running the rebuild-map.php script, which
+   *              will be 0 to indicate success or non-zero for failure.
+   */
   private function liberateCreateLibrary($path) {
     $init_path = $path.'/__phutil_library_init__.php';
     if (Filesystem::pathExists($init_path)) {
-      return;
+      return 0;
     }
 
     echo pht("Creating new libphutil library in '%s'.", $path)."\n";
@@ -213,7 +231,7 @@ EOTEXT
       '__phutil_library_init__.php',
       $path);
     Filesystem::writeFile($init_path, $template);
-    $this->liberateVersion2($path);
+    return $this->liberateVersion2($path);
   }
 
 

src/workflow/ArcanistPatchWorkflow.php

@@ -707,7 +707,7 @@ EOTEXT
         'git apply --whitespace nowarn --index --reject -- %s',
         $patchfile);
       $passthru->setCWD($repository_api->getPath());
-      $err = $passthru->execute();
+      $err = $passthru->resolve();
 
       if ($err) {
         echo phutil_console_format(
@@ -890,8 +890,8 @@ EOTEXT
           'revision_id' => $revision_id,
         ));
       $prompt_message = pht(
-        '  Note arcanist failed to load the commit message '.
+        '  NOTE: Failed to load the commit message from Differential (for '.
-        'from differential for revision %s.',
+        'revision "%s".)',
         "D{$revision_id}");
     }
 
@@ -909,6 +909,8 @@ EOTEXT
 
       $commit_message = $this->newInteractiveEditor($template)
         ->setName('arcanist-patch-commit-message')
+        ->setTaskMessage(pht(
+          'Supply a commit message for this patch, then save and exit.'))
         ->editInteractively();
 
       $commit_message = ArcanistCommentRemover::removeComments($commit_message);

src/workflow/ArcanistUpgradeWorkflow.php

@@ -9,12 +9,12 @@ final class ArcanistUpgradeWorkflow
 
   public function getWorkflowInformation() {
     $help = pht(<<<EOTEXT
-Upgrade Arcanist to the latest version.
+Upgrade this program to the latest version.
 EOTEXT
 );
 
     return $this->newWorkflowInformation()
-      ->setSynopsis(pht('Upgrade Arcanist to the latest version.'))
+      ->setSynopsis(pht('Upgrade this program to the latest version.'))
       ->addExample(pht('**upgrade**'))
       ->setHelp($help);
   }
@@ -51,10 +51,10 @@ EOTEXT
       if (!$is_git) {
         throw new PhutilArgumentUsageException(
           pht(
-            'The "arc upgrade" workflow uses "git pull" to upgrade '.
+            'The "upgrade" workflow uses "git pull" to upgrade, but '.
-            'Arcanist, but the "arcanist/" directory  (in "%s") is not a Git '.
+            'the software directory (in "%s") is not a Git working '.
-            'working copy. You must leave "arcanist/" as a Git '.
+            'copy. You must leave this directory as a Git working copy to '.
-            'working copy to use "arc upgrade".',
+            'use "arc upgrade".',
             $root));
       }
 
@@ -125,7 +125,7 @@ EOTEXT
 
     $log->writeSuccess(
       pht('UPGRADED'),
-      pht('Your copy of Arcanist is now up to date.'));
+      pht('This software is now up to date.'));
 
     return 0;
   }

src/workflow/ArcanistUploadWorkflow.php

@@ -9,7 +9,7 @@ final class ArcanistUploadWorkflow
 
   public function getWorkflowInformation() {
     $help = pht(<<<EOTEXT
-Upload one or more files from local disk to Phabricator.
+Upload one or more files from local disk.
 EOTEXT
 );
 

src/workflow/ArcanistWorkWorkflow.php

@@ -28,15 +28,15 @@ The __symbol__ may be a branch or bookmark name, a revision name (like "D123"),
 a task name (like "T123"), or a new symbol.
 
 If you provide a symbol which currently does not identify any ongoing work,
-Arcanist will create a new branch or bookmark with the name you provide.
+a new branch or bookmark will be created with the name you provide.
 
-If you provide the name of an existing branch or bookmark, Arcanist will switch
+If you provide the name of an existing branch or bookmark, the working copy
-to that branch or bookmark.
+will be switched to that branch or bookmark.
 
-If you provide the name of a revision or task, Arcanist will look for a related
+If you provide the name of a revision or task, the workflow will look for a
-branch or bookmark that exists in the working copy. If it finds one, it will
+related branch or bookmark that already exists in the working copy. If one is
-switch to it. If it does not find one, it will attempt to create a new branch
+found, it will switch to it. If it does not find one, it will attempt to create
-or bookmark.
+a new branch or bookmark.
 
 When "arc work" creates a branch or bookmark, it will use **--start** as the
 branchpoint if it is provided. Otherwise, the current working copy state will

src/workflow/ArcanistWorkflow.php

@@ -143,7 +143,7 @@ abstract class ArcanistWorkflow extends Phobject {
 
     if ($information) {
       $synopsis = $information->getSynopsis();
-      if (strlen($synopsis)) {
+      if ($synopsis !== null) {
         $phutil_workflow->setSynopsis($synopsis);
       }
 
@@ -154,7 +154,7 @@ abstract class ArcanistWorkflow extends Phobject {
       }
 
       $help = $information->getHelp();
-      if (strlen($help)) {
+      if ($help !== null) {
         // Unwrap linebreaks in the help text so we don't get weird formatting.
         $help = preg_replace("/(?<=\S)\n(?=\S)/", ' ', $help);
 
@@ -534,7 +534,7 @@ abstract class ArcanistWorkflow extends Phobject {
         $conduit_uri = $this->conduitURI;
         $message = phutil_console_format(
           "\n%s\n\n    %s\n\n%s\n%s",
-          pht('YOU NEED TO __INSTALL A CERTIFICATE__ TO LOGIN TO PHABRICATOR'),
+          pht('YOU NEED TO __INSTALL A CERTIFICATE__ TO LOG IN'),
           pht('To do this, run: **%s**', 'arc install-certificate'),
           pht("The server '%s' rejected your request:", $conduit_uri),
           $ex->getMessage());
@@ -1234,6 +1234,9 @@ abstract class ArcanistWorkflow extends Phobject {
 
         $commit_message = $this->newInteractiveEditor($template)
           ->setName(pht('commit-message'))
+          ->setTaskMessage(pht(
+            'Supply commit message for uncommitted changes, then save and '.
+            'exit.'))
           ->editInteractively();
 
         if ($commit_message === $template) {
@@ -1562,7 +1565,7 @@ abstract class ArcanistWorkflow extends Phobject {
    * @return void
    */
   final protected function writeStatusMessage($msg) {
-    fwrite(STDERR, $msg);
+    PhutilSystem::writeStderr($msg);
   }
 
   final public function writeInfo($title, $message) {
@@ -1954,11 +1957,10 @@ abstract class ArcanistWorkflow extends Phobject {
     } catch (ConduitClientException $ex) {
       if ($ex->getErrorCode() == 'ERR-CONDUIT-CALL') {
         $reasons[] = pht(
-          'This version of Arcanist is more recent than the version of '.
+          'This software version on the server you are connecting to is out '.
-          'Phabricator you are connecting to: the Phabricator install is '.
+          'of date and does not have support for identifying repositories '.
-          'out of date and does not have support for identifying '.
+          'by callsign or URI. Update the server sofwware to enable these '.
-          'repositories by callsign or URI. Update Phabricator to enable '.
+          'features.');
-          'these features.');
         return array(null, $reasons);
       }
       throw $ex;
@@ -2201,9 +2203,8 @@ abstract class ArcanistWorkflow extends Phobject {
 
     throw new ArcanistUsageException(
       pht(
-        "Unable to find a browser command to run. Set '%s' in your ".
+        'Unable to find a browser command to run. Set "browser" in your '.
-        "Arcanist config to specify a command to use.",
+        'configuration to specify a command to use.'));
-        'browser'));
   }
 
 

support/hg/arc-hg.py

@@ -21,18 +21,123 @@ from mercurial import (
   hg,
   i18n,
   node,
-  registrar,
 )
 
 _ = i18n._
 cmdtable = {}
-command = registrar.command(cmdtable)
+
+# Older veresions of Mercurial (~4.7) moved the command function and the
+# remoteopts object to different modules. Using try/except here to attempt
+# allowing this module to load properly, despite whether individual commands
+# will work properly on older versions of Mercurial or not.
+# https://phab.mercurial-scm.org/rHG46ba2cdda476ac53a8a8f50e4d9435d88267db60
+# https://phab.mercurial-scm.org/rHG04baab18d60a5c833ab3190506147e01b3c6d12c
+try:
+  from mercurial import registrar
+  command = registrar.command(cmdtable)
+except:
+  command = cmdutil.command(cmdtable)
+
+try:
+  remoteopts = cmdutil.remoteopts
+except:
+  from mercurial import commands
+  remoteopts = commands.remoteopts
+
+try:
+  parseurl = hg.parseurl
+except:
+  from mercurial import utils
+  parseurl = utils.urlutil.parseurl
+
+@command(
+  b'arc-amend',
+  [
+    (b'l',
+      b'logfile',
+      b'',
+      _(b'read commit message from file'),
+      _(b'FILE')),
+    (b'm',
+      b'message',
+      b'',
+      _(b'use text as commit message'),
+      _(b'TEXT')),
+    (b'u',
+      b'user',
+      b'',
+      _(b'record the specified user as committer'),
+      _(b'USER')),
+    (b'd',
+      b'date',
+      b'',
+      _(b'record the specified date as commit date'),
+      _(b'DATE')),
+    (b'A',
+      b'addremove',
+      False,
+      _(b'mark new/missing files as added/removed before committing')),
+    (b'n',
+      b'note',
+      b'',
+      _(b'store a note on amend'),
+      _(b'TEXT')),
+  ],
+  _(b'[OPTION]'))
+def amend(ui, repo, source=None, **opts):
+  """amend
+
+  Uses Mercurial internal API to amend changes to a non-head commit.
+
+  (This is an Arcanist extension to Mercurial.)
+
+  Returns 0 if amending succeeds, 1 otherwise.
+  """
+
+  # The option keys seem to come in as 'str' type but the cmdutil.amend() code
+  # expects them as binary. To account for both Python 2 and Python 3
+  # compatibility, insert the value under both 'str' and binary type.
+  newopts = {}
+  for key in opts:
+    val = opts.get(key)
+    newopts[key] = val
+    if isinstance(key, str):
+      newkey = key.encode('UTF-8')
+      newopts[newkey] = val
+
+  orig = repo[b'.']
+  extra = {}
+  pats = []
+  cmdutil.amend(ui, repo, orig, extra, pats, newopts)
+
+  """
+  # This will allow running amend on older versions of Mercurial, ~3.5, however
+  # the behavior on those versions will squash child commits of the working
+  # directory into the amended commit which is undesired.
+  try:
+    cmdutil.amend(ui, repo, orig, extra, pats, newopts)
+  except:
+    def commitfunc(ui, repo, message, match, opts):
+      return repo.commit(
+        message,
+        opts.get('user') or orig.user(),
+        opts.get('date') or orig.date(),
+        match,
+        extra=extra)
+    cmdutil.amend(ui, repo, commitfunc, orig, extra, pats, newopts)
+  """
+
+  return 0
 
 @command(
   b'arc-ls-markers',
-  [(b'', b'output', b'',
+  [
-    _(b'file to output refs to'), _(b'FILE')),
+    (b'',
-  ] + cmdutil.remoteopts,
+      b'output',
+      b'',
+    _(b'file to output refs to'),
+    _(b'FILE')),
+  ] + remoteopts,
   _(b'[--output FILENAME] [SOURCE]'))
 def lsmarkers(ui, repo, source=None, **opts):
   """list markers
@@ -168,7 +273,7 @@ def remotemarkers(ui, repo, source, opts):
 
   markers = []
 
-  source, branches = hg.parseurl(ui.expandpath(source))
+  source, branches = parseurl(ui.expandpath(source))
   remote = hg.peer(repo, opts, source)
 
   with remote.commandexecutor() as e: