diff --git a/src/error/PhutilErrorHandler.php b/src/error/PhutilErrorHandler.php
index 63d5b492..2fc8fe7d 100644
--- a/src/error/PhutilErrorHandler.php
+++ b/src/error/PhutilErrorHandler.php
@@ -6,7 +6,7 @@
  *
  * This class takes over the PHP error and exception handlers when you call
  * ##PhutilErrorHandler::initialize()## and forwards all debugging information
- * to a listener you install with ##PhutilErrorHandler::setErrorListener()##.
+ * to a listener you install with ##PhutilErrorHandler::addErrorListener()##.
  *
  * To use PhutilErrorHandler, which will enhance the messages printed to the
  * PHP error log, just initialize it:
@@ -16,7 +16,7 @@
  * To additionally install a custom listener which can print error information
  * to some other file or console, register a listener:
  *
- *    PhutilErrorHandler::setErrorListener($some_callback);
+ *    PhutilErrorHandler::addErrorListener($some_callback);
  *
  * For information on writing an error listener, see
  * @{function:phutil_error_listener_example}. Providing a listener is optional,
@@ -31,7 +31,7 @@
  */
 final class PhutilErrorHandler extends Phobject {
 
-  private static $errorListener = null;
+  private static $errorListeners = array();
   private static $initialized = false;
   private static $traps = array();
 
@@ -68,8 +68,15 @@ final class PhutilErrorHandler extends Phobject {
    * @return void
    * @task config
    */
+  public static function addErrorListener($listener) {
+    self::$errorListeners[] = $listener;
+  }
+
+  /**
+   * Deprecated - use `addErrorListener`.
+   */
   public static function setErrorListener($listener) {
-    self::$errorListener = $listener;
+    self::addErrorListener($listener);
   }
 
 
@@ -203,12 +210,17 @@ final class PhutilErrorHandler extends Phobject {
 
     if (($num === E_USER_ERROR) ||
         ($num === E_USER_WARNING) ||
-        ($num === E_USER_NOTICE)) {
+        ($num === E_USER_NOTICE) ||
+        ($num === E_DEPRECATED)) {
+
+      // See T15554 - we special-case E_DEPRECATED because we don't want them
+      // to kill the process.
+      $level = ($num === E_DEPRECATED) ? self::DEPRECATED : self::ERROR;
 
       $trace = debug_backtrace();
       array_shift($trace);
       self::dispatchErrorMessage(
-        self::ERROR,
+        $level,
         $str,
         array(
           'file'       => $file,
@@ -380,6 +392,7 @@ final class PhutilErrorHandler extends Phobject {
     $timestamp = date('Y-m-d H:i:s');
 
     switch ($event) {
+      case self::DEPRECATED:
       case self::ERROR:
         $default_message = sprintf(
           '[%s] ERROR %d: %s at [%s:%d]',
@@ -432,7 +445,7 @@ final class PhutilErrorHandler extends Phobject {
         break;
     }
 
-    if (self::$errorListener) {
+    if (self::$errorListeners) {
       static $handling_error;
       if ($handling_error) {
         error_log(
@@ -441,7 +454,9 @@ final class PhutilErrorHandler extends Phobject {
         return;
       }
       $handling_error = true;
-      call_user_func(self::$errorListener, $event, $value, $metadata);
+      foreach (self::$errorListeners as $error_listener) {
+        call_user_func($error_listener, $event, $value, $metadata);
+      }
       $handling_error = false;
     }
   }
diff --git a/src/error/phlog.php b/src/error/phlog.php
index 105e0740..52dc6af9 100644
--- a/src/error/phlog.php
+++ b/src/error/phlog.php
@@ -41,7 +41,7 @@ function phlog($value/* , ... */) {
 
 /**
  * Example @{class:PhutilErrorHandler} error listener callback. When you call
- * `PhutilErrorHandler::setErrorListener()`, you must pass a callback function
+ * `PhutilErrorHandler::addErrorListener()`, you must pass a callback function
  * with the same signature as this one.
  *
  * NOTE: @{class:PhutilErrorHandler} handles writing messages to the error
diff --git a/src/filesystem/Filesystem.php b/src/filesystem/Filesystem.php
index 9cd52268..981d4feb 100644
--- a/src/filesystem/Filesystem.php
+++ b/src/filesystem/Filesystem.php
@@ -1103,12 +1103,23 @@ final class Filesystem extends Phobject {
         }
         return null;
       }
-      $stdout = head($stdout);
+
+      // These are the only file extensions that can be executed directly
+      // when using proc_open() with 'bypass_shell'.
+      $executable_extensions = ['exe', 'bat', 'cmd', 'com'];
+
+      foreach ($stdout as $line) {
+        $path = trim($line);
+        $ext = pathinfo($path, PATHINFO_EXTENSION);
+        if (in_array($ext, $executable_extensions)) {
+          return $path;
+        }
+      }
+      return null;
     } else {
       list($err, $stdout) = exec_manual('which %s', $binary);
+      return $err === 0 ? trim($stdout) : null;
     }
-
-    return $err === 0 ? trim($stdout) : null;
   }
 
 
diff --git a/src/filesystem/PhutilErrorLog.php b/src/filesystem/PhutilErrorLog.php
index d652d854..a9ec08a4 100644
--- a/src/filesystem/PhutilErrorLog.php
+++ b/src/filesystem/PhutilErrorLog.php
@@ -83,7 +83,7 @@ final class PhutilErrorLog
   }
 
   public function onError($event, $value, array $metadata) {
-    // If we've set "error_log" to a real file, so messages won't be output to
+    // If we've set "error_log" to a real file, messages won't be output to
     // stderr by default. Copy them to stderr.
 
     if ($this->logPath === null) {
diff --git a/src/future/oauth/PhutilOAuth1Future.php b/src/future/oauth/PhutilOAuth1Future.php
index 8edd6c26..f73b9db0 100644
--- a/src/future/oauth/PhutilOAuth1Future.php
+++ b/src/future/oauth/PhutilOAuth1Future.php
@@ -229,7 +229,10 @@ final class PhutilOAuth1Future extends FutureProxy {
       $consumer_secret = $this->consumerSecret->openEnvelope();
     }
 
-    $key = urlencode($consumer_secret).'&'.urlencode($this->tokenSecret);
+    $key = urlencode($consumer_secret).'&';
+    if ($this->tokenSecret !== null) {
+      $key .= urlencode($this->tokenSecret);
+    }
 
     switch ($this->signatureMethod) {
       case 'HMAC-SHA1':
diff --git a/src/lint/linter/ArcanistComposerLinter.php b/src/lint/linter/ArcanistComposerLinter.php
index a9eded3e..c46657e0 100644
--- a/src/lint/linter/ArcanistComposerLinter.php
+++ b/src/lint/linter/ArcanistComposerLinter.php
@@ -37,11 +37,12 @@ final class ArcanistComposerLinter extends ArcanistLinter {
   }
 
   private function lintComposerJson($path) {
-    $composer_hash = md5(Filesystem::readFile(dirname($path).'/composer.json'));
+    $composer_hash = self::getContentHash(
+      Filesystem::readFile(dirname($path).'/composer.json'));
     $composer_lock = phutil_json_decode(
       Filesystem::readFile(dirname($path).'/composer.lock'));
 
-    if ($composer_hash !== $composer_lock['hash']) {
+    if ($composer_hash !== $composer_lock['content-hash']) {
       $this->raiseLintAtPath(
         self::LINT_OUT_OF_DATE,
         pht(
@@ -52,4 +53,68 @@ final class ArcanistComposerLinter extends ArcanistLinter {
     }
   }
 
+  /**
+   * Returns the md5 hash of the sorted content of the composer.json file.
+   *
+   * This function copied from
+   * https://github.com/
+   * composer/composer/blob/1.5.2/src/Composer/Package/Locker.php
+   * and has the following license:
+   *
+   * Copyright (c) Nils Adermann, Jordi Boggiano
+   *
+   * Permission is hereby granted, free of charge, to any person obtaining a
+   * copy of this software and associated documentation files (the "Software"),
+   * to deal in the Software without restriction, including without limitation
+   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   * and/or sell copies of the Software, and to permit persons to whom the
+   * Software is furnished to do so, subject to the following conditions:
+   *
+   * The above copyright notice and this permission notice shall be included in
+   * all copies or substantial portions of the Software.
+   *
+   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+   * DEALINGS IN THE SOFTWARE.
+   *
+   *
+   * @param string $composer_file_contents The contents of the composer file.
+   *
+   * @return string
+   */
+  public static function getContentHash($composer_file_contents) {
+    $content = json_decode($composer_file_contents, true);
+
+    $relevant_keys = array(
+      'name',
+      'version',
+      'require',
+      'require-dev',
+      'conflict',
+      'replace',
+      'provide',
+      'minimum-stability',
+      'prefer-stable',
+      'repositories',
+      'extra',
+    );
+
+    $relevant_content = array();
+
+    foreach (array_intersect($relevant_keys, array_keys($content)) as $key) {
+      $relevant_content[$key] = $content[$key];
+    }
+    if (isset($content['config']['platform'])) {
+      $relevant_content['config']['platform'] = $content['config']['platform'];
+    }
+
+    ksort($relevant_content);
+
+    return md5(json_encode($relevant_content));
+  }
+
 }
diff --git a/src/lint/linter/ArcanistExternalLinter.php b/src/lint/linter/ArcanistExternalLinter.php
index a394528f..8c35e440 100644
--- a/src/lint/linter/ArcanistExternalLinter.php
+++ b/src/lint/linter/ArcanistExternalLinter.php
@@ -133,7 +133,19 @@ abstract class ArcanistExternalLinter extends ArcanistFutureLinter {
    * @task bin
    */
   final public function getBinary() {
-    return coalesce($this->bin, $this->getDefaultBinary());
+    $bin = coalesce($this->bin, $this->getDefaultBinary());
+    if (phutil_is_windows()) {
+      // On Windows, we use proc_open with 'bypass_shell' option, which will
+      // resolve %PATH%, but not %PATHEXT% (unless the extension is .exe).
+      // Therefore find the right binary ourselves.
+      // If we can't find it, leave it unresolved, as this string will be
+      // used in some error messages elsewhere.
+      $resolved = Filesystem::resolveBinary($bin);
+      if ($resolved) {
+        return $resolved;
+      }
+    }
+    return $bin;
   }
 
   /**
diff --git a/src/lint/linter/__tests__/jshint/too-many-errors.lint-test b/src/lint/linter/__tests__/jshint/too-many-errors.lint-test
index e7b936dd..bc33c0dd 100644
--- a/src/lint/linter/__tests__/jshint/too-many-errors.lint-test
+++ b/src/lint/linter/__tests__/jshint/too-many-errors.lint-test
@@ -1,5 +1,6 @@
 /* jshint maxerr: 1 */
-console.log('foobar')
+console.log(
+{
 ~~~~~~~~~~
-disabled:2:22:E043
-warning:2:22:W033
+disabled:3:1:E043
+error:3:1:E019
diff --git a/src/lint/linter/__tests__/xml/languages-6.lint-test b/src/lint/linter/__tests__/xml/languages-6.lint-test
index f652fbb8..7f14c97f 100644
--- a/src/lint/linter/__tests__/xml/languages-6.lint-test
+++ b/src/lint/linter/__tests__/xml/languages-6.lint-test
@@ -3,5 +3,5 @@
     </lang>
 </languages>
 ~~~~~~~~~~
-error:3:16:XML76:LibXML Error
+error:3:12:XML76:LibXML Error
 error:4:1:XML5:LibXML Error
diff --git a/src/moduleutils/PhutilLibraryMapBuilder.php b/src/moduleutils/PhutilLibraryMapBuilder.php
index f51fc464..df05050a 100644
--- a/src/moduleutils/PhutilLibraryMapBuilder.php
+++ b/src/moduleutils/PhutilLibraryMapBuilder.php
@@ -469,10 +469,12 @@ EOPHP;
 
     $this->fileSymbolMap = $symbol_map;
 
-    // We're done building the cache, so write it out immediately. Note that
-    // we've only retained entries for files we found, so this implicitly cleans
-    // out old cache entries.
-    $this->writeSymbolCache($symbol_map, $source_map);
+    if ($futures) {
+      // We're done building/updating the cache, so write it out immediately.
+      // Note that we've only retained entries for files we found, so this
+      // implicitly cleans out old cache entries.
+      $this->writeSymbolCache($symbol_map, $source_map);
+    }
 
     // Our map is up to date, so either show it on stdout or write it to disk.
     $this->librarySymbolMap = $this->buildLibraryMap($symbol_map);
diff --git a/src/parser/ArcanistBundle.php b/src/parser/ArcanistBundle.php
index 4617c9b6..62deca5e 100644
--- a/src/parser/ArcanistBundle.php
+++ b/src/parser/ArcanistBundle.php
@@ -762,7 +762,7 @@ final class ArcanistBundle extends Phobject {
       $old_data = $this->getBlob($old_phid, $name);
     }
 
-    $old_length = strlen($old_data);
+    $old_length = phutil_nonempty_string($old_data) ? strlen($old_data) : 0;
 
     // Here, and below, the binary will be emitted with base85 encoding. This
     // encoding encodes each 4 bytes of input in 5 bytes of output, so we may
@@ -795,7 +795,7 @@ final class ArcanistBundle extends Phobject {
       $new_data = $this->getBlob($new_phid, $name);
     }
 
-    $new_length = strlen($new_data);
+    $new_length = phutil_nonempty_string($new_data) ? strlen($new_data) : 0;
     $this->reserveBytes($new_length * 5 / 4);
 
     if ($new_data === null) {
diff --git a/src/platform/PlatformSymbols.php b/src/platform/PlatformSymbols.php
index 1b02b775..2529780e 100644
--- a/src/platform/PlatformSymbols.php
+++ b/src/platform/PlatformSymbols.php
@@ -11,6 +11,14 @@ final class PlatformSymbols
     return 'Phorge';
   }
 
+  public static function getPlatformClientPath() {
+    return 'arcanist/';
+  }
+
+  public static function getPlatformServerPath() {
+    return 'phorge/';
+  }
+
   public static function getProductNames() {
     return array(
       self::getPlatformClientName(),
diff --git a/src/utils/PhutilCowsay.php b/src/utils/PhutilCowsay.php
index ccbeccf4..aeabf145 100644
--- a/src/utils/PhutilCowsay.php
+++ b/src/utils/PhutilCowsay.php
@@ -41,44 +41,44 @@ final class PhutilCowsay extends Phobject {
     $template = $this->template;
 
     // Real ".cow" files are Perl scripts which define a variable called
-    // "$the_cow". We aren't going to interpret Perl, so strip all this stuff
-    // (and any comments in the file) away.
-    $template = phutil_split_lines($template, true);
-    $keep = array();
-    $is_perl_cowfile = false;
-    foreach ($template as $key => $line) {
-      if (preg_match('/^#/', $line)) {
-        continue;
-      }
-      if (preg_match('/^\s*\\$the_cow/', $line)) {
-        $is_perl_cowfile = true;
-        continue;
-      }
-      if (preg_match('/^\s*EOC\s*$/', $line)) {
-        continue;
-      }
-      $keep[] = $line;
-    }
-    $template = implode('', $keep);
+    // "$the_cow". We aren't going to interpret Perl, so just get everything
+    // between the EOC (End Of Cow) tokens. The initial EOC might be in
+    // quotes, and might have a semicolon.
+    // We apply regexp modifiers
+    // * 's' to make . match newlines within the EOC ... EOC block
+    // * 'm' so we can use ^ to match start of line within the multiline string
+    $matches = null;
+    if (
+      preg_match('/\$the_cow/', $template) &&
+      preg_match('/EOC[\'"]?;?.*?^(.*?)^EOC/sm', $template, $matches)
+    ) {
+      $template = $matches[1];
 
-    // Original .cow files are perl scripts which contain escaped sequences.
-    // We attempt to unescape here by replacing any character preceded by a
-    // backslash/escape with just that character.
-    if ($is_perl_cowfile) {
+      // Original .cow files are perl scripts which contain escaped sequences.
+      // We attempt to unescape here by replacing any character preceded by a
+      // backslash/escape with just that character.
       $template = preg_replace(
         '/\\\\(.)/',
         '$1',
         $template);
+    } else {
+      // Text template. Just strip away comments.
+      $template = preg_replace('/^#.*$/', '', $template);
     }
 
-    $template = preg_replace_callback(
+    $token_patterns = array(
       '/\\$([a-z]+)/',
-      array($this, 'replaceTemplateVariable'),
-      $template);
-    if ($template === false) {
-      throw new Exception(
-        pht(
-          'Failed to replace template variables while rendering cow!'));
+      '/\\${([a-z]+)}/',
+    );
+    foreach ($token_patterns as $token_pattern) {
+      $template = preg_replace_callback(
+        $token_pattern,
+        array($this, 'replaceTemplateVariable'),
+        $template);
+      if ($template === false) {
+        throw new Exception(
+          pht('Failed to replace template variables while rendering cow!'));
+      }
     }
 
     $lines = $this->text;
diff --git a/src/utils/__tests__/cowsay/cube_perl.test b/src/utils/__tests__/cowsay/cube_perl.test
index d9582d2b..a950e588 100644
--- a/src/utils/__tests__/cowsay/cube_perl.test
+++ b/src/utils/__tests__/cowsay/cube_perl.test
@@ -1,5 +1,5 @@
 # test case for original perl-script cowfile
-$the_cow =
+$the_cow = <<EOC
  $thoughts
   $thoughts
     /---\\__/---\\\\
@@ -9,6 +9,7 @@ $the_cow =
      / ..--.. \\\\
     | \\ .... / ||
     \\---/--\\---//
+EOC
 ~~~~~~~~~~
 {
   "text": "I made a friend!",
diff --git a/src/utils/__tests__/cowsay/sheep.expect b/src/utils/__tests__/cowsay/sheep.expect
new file mode 100644
index 00000000..ee5d1c08
--- /dev/null
+++ b/src/utils/__tests__/cowsay/sheep.expect
@@ -0,0 +1,11 @@
+ __________________
+< How are my eyes? >
+ ------------------
+  \
+   \
+       __
+      UooU\.'@@@@@@`.
+      \__/(@@@@@@@@@@)
+           (@@@@@@@@)
+           `YY~~~~YY'
+            ||    ||
diff --git a/src/utils/__tests__/cowsay/sheep.test b/src/utils/__tests__/cowsay/sheep.test
new file mode 100644
index 00000000..abd54dfc
--- /dev/null
+++ b/src/utils/__tests__/cowsay/sheep.test
@@ -0,0 +1,13 @@
+  $thoughts
+   $thoughts
+       __
+      U${eyes}U\.'@@@@@@`.
+      \__/(@@@@@@@@@@)
+           (@@@@@@@@)
+           `YY~~~~YY'
+            ||    ||
+~~~~~~~~~~
+{
+  "text": "How are my eyes?",
+  "eyes": "oo"
+}
diff --git a/src/utils/__tests__/cowsay/small.expect b/src/utils/__tests__/cowsay/small.expect
new file mode 100644
index 00000000..9d112578
--- /dev/null
+++ b/src/utils/__tests__/cowsay/small.expect
@@ -0,0 +1,7 @@
+ __________________
+< How are my eyes? >
+ ------------------
+       \   ,__,
+        \  (oo)____
+           (__)    )\
+              ||--|| *
diff --git a/src/utils/__tests__/cowsay/small.test b/src/utils/__tests__/cowsay/small.test
new file mode 100644
index 00000000..bc3e08e4
--- /dev/null
+++ b/src/utils/__tests__/cowsay/small.test
@@ -0,0 +1,12 @@
+$eyes = ".." unless ($eyes);
+$the_cow = <<EOC;
+       $thoughts   ,__,
+        $thoughts  ($eyes)____
+           (__)    )\\
+            $tongue||--|| *
+EOC
+~~~~~~~~~~
+{
+  "text": "How are my eyes?",
+  "eyes": "oo"
+}
diff --git a/src/workflow/ArcanistWorkflow.php b/src/workflow/ArcanistWorkflow.php
index 3a855025..d0863772 100644
--- a/src/workflow/ArcanistWorkflow.php
+++ b/src/workflow/ArcanistWorkflow.php
@@ -479,8 +479,8 @@ abstract class ArcanistWorkflow extends Phobject {
       // If we have `token`, this server supports the simpler, new-style
       // token-based authentication. Use that instead of all the certificate
       // stuff.
-      $token = idx($credentials, 'token', '');
-      if (strlen($token)) {
+      $token = idx($credentials, 'token');
+      if (phutil_nonempty_string($token)) {
         $conduit = $this->getConduit();
 
         $conduit->setConduitToken($token);
@@ -2244,8 +2244,8 @@ abstract class ArcanistWorkflow extends Phobject {
   protected function getModernUnitDictionary(array $map) {
     $map = $this->getModernCommonDictionary($map);
 
-    $details = idx($map, 'userData', '');
-    if (strlen($details)) {
+    $details = idx($map, 'userData');
+    if (phutil_nonempty_string($details)) {
       $map['details'] = (string)$details;
     }
     unset($map['userData']);