Allow "blame previous revision" to track file moves and handle edge cases

Summary:
  - Track + message through file moves.
  - Stop + message on file create.
  - Stop + message on first commit.

Test Plan:
  - Tested blaming through a move, through a create, and through the first commit.
  - Verified this doesn't break anything in SVN / Mercurial.

Reviewers: vrana, btrahan, jungejason

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1091

Differential Revision: https://secure.phabricator.com/D2295

src/__phutil_library_map__.php

@@ -321,6 +321,7 @@ phutil_register_library_map(array(
     'DiffusionGitHistoryQuery' => 'applications/diffusion/query/history/git',
     'DiffusionGitLastModifiedQuery' => 'applications/diffusion/query/lastmodified/git',
     'DiffusionGitMergedCommitsQuery' => 'applications/diffusion/query/mergedcommits/git',
+    'DiffusionGitRenameHistoryQuery' => 'applications/diffusion/query/renamehistory/git',
     'DiffusionGitRequest' => 'applications/diffusion/request/git',
     'DiffusionGitTagListQuery' => 'applications/diffusion/query/taglist/git',
     'DiffusionHistoryController' => 'applications/diffusion/controller/history',
@@ -339,6 +340,7 @@ phutil_register_library_map(array(
     'DiffusionMercurialHistoryQuery' => 'applications/diffusion/query/history/mercurial',
     'DiffusionMercurialLastModifiedQuery' => 'applications/diffusion/query/lastmodified/mercurial',
     'DiffusionMercurialMergedCommitsQuery' => 'applications/diffusion/query/mergedcommits/mercurial',
+    'DiffusionMercurialRenameHistoryQuery' => 'applications/diffusion/query/renamehistory/mercurial',
     'DiffusionMercurialRequest' => 'applications/diffusion/request/mercurial',
     'DiffusionMercurialTagListQuery' => 'applications/diffusion/query/taglist/mercurial',
     'DiffusionMergedCommitsQuery' => 'applications/diffusion/query/mergedcommits/base',
@@ -350,6 +352,7 @@ phutil_register_library_map(array(
     'DiffusionPathQueryTestCase' => 'applications/diffusion/query/pathid/base/__tests__',
     'DiffusionPathValidateController' => 'applications/diffusion/controller/pathvalidate',
     'DiffusionQuery' => 'applications/diffusion/query/base',
+    'DiffusionRenameHistoryQuery' => 'applications/diffusion/query/renamehistory/base',
     'DiffusionRepositoryController' => 'applications/diffusion/controller/repository',
     'DiffusionRepositoryPath' => 'applications/diffusion/data/repositorypath',
     'DiffusionRepositoryTag' => 'applications/diffusion/tag',
@@ -362,6 +365,7 @@ phutil_register_library_map(array(
     'DiffusionSvnHistoryQuery' => 'applications/diffusion/query/history/svn',
     'DiffusionSvnLastModifiedQuery' => 'applications/diffusion/query/lastmodified/svn',
     'DiffusionSvnMergedCommitsQuery' => 'applications/diffusion/query/mergedcommits/svn',
+    'DiffusionSvnRenameHistoryQuery' => 'applications/diffusion/query/renamehistory/svn',
     'DiffusionSvnRequest' => 'applications/diffusion/request/svn',
     'DiffusionSvnTagListQuery' => 'applications/diffusion/query/taglist/svn',
     'DiffusionSymbolController' => 'applications/diffusion/controller/symbol',
@@ -1282,6 +1286,7 @@ phutil_register_library_map(array(
     'DiffusionGitHistoryQuery' => 'DiffusionHistoryQuery',
     'DiffusionGitLastModifiedQuery' => 'DiffusionLastModifiedQuery',
     'DiffusionGitMergedCommitsQuery' => 'DiffusionMergedCommitsQuery',
+    'DiffusionGitRenameHistoryQuery' => 'DiffusionRenameHistoryQuery',
     'DiffusionGitRequest' => 'DiffusionRequest',
     'DiffusionGitTagListQuery' => 'DiffusionTagListQuery',
     'DiffusionHistoryController' => 'DiffusionController',
@@ -1300,12 +1305,14 @@ phutil_register_library_map(array(
     'DiffusionMercurialHistoryQuery' => 'DiffusionHistoryQuery',
     'DiffusionMercurialLastModifiedQuery' => 'DiffusionLastModifiedQuery',
     'DiffusionMercurialMergedCommitsQuery' => 'DiffusionMergedCommitsQuery',
+    'DiffusionMercurialRenameHistoryQuery' => 'DiffusionRenameHistoryQuery',
     'DiffusionMercurialRequest' => 'DiffusionRequest',
     'DiffusionMercurialTagListQuery' => 'DiffusionTagListQuery',
     'DiffusionMergedCommitsQuery' => 'DiffusionQuery',
     'DiffusionPathCompleteController' => 'DiffusionController',
     'DiffusionPathQueryTestCase' => 'PhabricatorTestCase',
     'DiffusionPathValidateController' => 'DiffusionController',
+    'DiffusionRenameHistoryQuery' => 'DiffusionQuery',
     'DiffusionRepositoryController' => 'DiffusionController',
     'DiffusionSvnBrowseQuery' => 'DiffusionBrowseQuery',
     'DiffusionSvnCommitParentsQuery' => 'DiffusionCommitParentsQuery',
@@ -1315,6 +1322,7 @@ phutil_register_library_map(array(
     'DiffusionSvnHistoryQuery' => 'DiffusionHistoryQuery',
     'DiffusionSvnLastModifiedQuery' => 'DiffusionLastModifiedQuery',
     'DiffusionSvnMergedCommitsQuery' => 'DiffusionMergedCommitsQuery',
+    'DiffusionSvnRenameHistoryQuery' => 'DiffusionRenameHistoryQuery',
     'DiffusionSvnRequest' => 'DiffusionRequest',
     'DiffusionSvnTagListQuery' => 'DiffusionTagListQuery',
     'DiffusionSymbolController' => 'DiffusionController',

src/applications/diffusion/controller/file/DiffusionBrowseFileController.php

@@ -69,6 +69,39 @@ final class DiffusionBrowseFileController extends DiffusionController {
         'path'   => true,
         'view'   => 'browse',
       ));
+
+    $follow  = $request->getStr('follow');
+    if ($follow) {
+      $notice = new AphrontErrorView();
+      $notice->setSeverity(AphrontErrorView::SEVERITY_WARNING);
+      $notice->setTitle('Unable to Continue');
+      switch ($follow) {
+        case 'first':
+          $notice->appendChild(
+            "Unable to continue tracing the history of this file because ".
+            "this commit is the first commit in the repository.");
+          break;
+        case 'created':
+          $notice->appendChild(
+            "Unable to continue tracing the history of this file because ".
+            "this commit created the file.");
+          break;
+      }
+      $content[] = $notice;
+    }
+
+    $renamed = $request->getStr('renamed');
+    if ($renamed) {
+      $notice = new AphrontErrorView();
+      $notice->setSeverity(AphrontErrorView::SEVERITY_NOTICE);
+      $notice->setTitle('File Renamed');
+      $notice->appendChild(
+        "File history passes through a rename from '".
+        phutil_escape_html($drequest->getPath())."' to '".
+        phutil_escape_html($renamed)."'.");
+      $content[] = $notice;
+    }
+
     $content[] = $view_select_panel;
     $content[] = $corpus;
     $content[] = $this->buildOpenRevisions();
@@ -612,30 +645,82 @@ final class DiffusionBrowseFileController extends DiffusionController {
     $request = $this->getRequest();
     $drequest = $this->getDiffusionRequest();
 
-    $before_req = DiffusionRequest::newFromDictionary(
-      array(
-        'repository' => $drequest->getRepository(),
-        'commit'     => $before,
-      ));
+    // NOTE: We need to get the grandparent so we can capture filename changes
+    // in the parent.
 
-    $query = DiffusionCommitParentsQuery::newFromDiffusionRequest($before_req);
-    $parents = $query->loadParents();
-    $parent = head($parents);
+    $parent = $this->loadParentRevisionOf($before);
+    $old_filename = null;
+    $was_created = false;
+    if ($parent) {
+      $grandparent = $this->loadParentRevisionOf(
+        $parent->getCommitIdentifier());
 
-    // NOTE: If they get back to the very first commit, we just keep them there.
-    // We could maybe show a message or something.
+      if ($grandparent) {
+        $rename_query = DiffusionRenameHistoryQuery::newFromDiffusionRequest(
+          $drequest);
+        $rename_query->setOldCommit($grandparent->getCommitIdentifier());
+        $old_filename = $rename_query->loadOldFilename();
+        $was_created = $rename_query->getWasCreated();
+      }
+    }
+
+    $follow = null;
+    if ($was_created) {
+      // If the file was created in history, that means older commits won't
+      // have it. Since we know it existed at 'before', it must have been
+      // created then; jump there.
+      $target_commit = $before;
+      $follow = 'created';
+    } else if ($parent) {
+      // If we found a parent, jump to it. This is the normal case.
+      $target_commit = $parent->getCommitIdentifier();
+    } else {
+      // If there's no parent, this was probably created in the initial commit?
+      // And the "was_created" check will fail because we can't identify the
+      // grandparent. Keep the user at 'before'.
+      $target_commit = $before;
+      $follow = 'first';
+    }
+
+    $path = $drequest->getPath();
+    $renamed = null;
+    if ($old_filename !== null &&
+        $old_filename !== $path) {
+      $renamed = $path;
+      $path = $old_filename;
+    }
 
     $before_uri = $drequest->generateURI(
       array(
         'action'    => 'browse',
-        'commit'    => $parent ? $parent->getCommitIdentifier() : $before,
-        'line'      => $drequest->getLine(),
+        'commit'    => $target_commit,
+        // If there's a follow error, drop the line so the user sees the
+        // message.
+        'line'      => $follow ? null : $drequest->getLine(),
+        'path'      => $path,
       ));
 
     $before_uri->setQueryParams($request->getRequestURI()->getQueryParams());
     $before_uri = $before_uri->alter('before', null);
+    $before_uri = $before_uri->alter('renamed', $renamed);
+    $before_uri = $before_uri->alter('follow', $follow);
 
     return id(new AphrontRedirectResponse())->setURI($before_uri);
   }
 
+  private function loadParentRevisionOf($commit) {
+    $drequest = $this->getDiffusionRequest();
+
+    $before_req = DiffusionRequest::newFromDictionary(
+      array(
+        'repository' => $drequest->getRepository(),
+        'commit'     => $commit,
+      ));
+
+    $query = DiffusionCommitParentsQuery::newFromDiffusionRequest($before_req);
+    $parents = $query->loadParents();
+
+    return head($parents);
+  }
+
 }

src/applications/diffusion/controller/file/__init__.php

@@ -14,6 +14,7 @@ phutil_require_module('phabricator', 'applications/audit/query/commit');
 phutil_require_module('phabricator', 'applications/diffusion/controller/base');
 phutil_require_module('phabricator', 'applications/diffusion/query/filecontent/base');
 phutil_require_module('phabricator', 'applications/diffusion/query/parents/base');
+phutil_require_module('phabricator', 'applications/diffusion/query/renamehistory/base');
 phutil_require_module('phabricator', 'applications/diffusion/request/base');
 phutil_require_module('phabricator', 'applications/files/storage/file');
 phutil_require_module('phabricator', 'applications/markup/syntax');
@@ -22,6 +23,7 @@ phutil_require_module('phabricator', 'infrastructure/javelin/api');
 phutil_require_module('phabricator', 'infrastructure/javelin/markup');
 phutil_require_module('phabricator', 'infrastructure/util/hash');
 phutil_require_module('phabricator', 'view/form/control/select');
+phutil_require_module('phabricator', 'view/form/error');
 phutil_require_module('phabricator', 'view/layout/panel');
 phutil_require_module('phabricator', 'view/utils');
 

src/applications/diffusion/query/history/git/DiffusionGitHistoryQuery.php

@@ -38,10 +38,14 @@ final class DiffusionGitHistoryQuery extends DiffusionHistoryQuery {
       // Git omits merge commits if the path is provided, even if it is empty.
       (strlen($path) ? csprintf('%s', $path) : ''));
 
+    $lines = explode("\n", trim($stdout));
+    $lines = array_filter($lines);
+    if (!$lines) {
+      return array();
+    }
+
     $hash_list = array();
     $parent_map = array();
-
-    $lines = explode("\n", trim($stdout));
     foreach ($lines as $line) {
       list($hash, $parents) = explode(":", $line);
       $hash_list[] = $hash;

src/applications/diffusion/query/renamehistory/base/DiffusionRenameHistoryQuery.php

@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+abstract class DiffusionRenameHistoryQuery extends DiffusionQuery {
+
+  private $oldCommit;
+  private $wasCreated;
+
+  protected function setWasCreated($was_created) {
+    $this->wasCreated = $was_created;
+    return $this;
+  }
+
+  public function getWasCreated() {
+    return $this->wasCreated;
+  }
+
+  public function setOldCommit($old_commit) {
+    $this->oldCommit = $old_commit;
+    return $this;
+  }
+
+  public function getOldCommit() {
+    return $this->oldCommit;
+  }
+
+  final public static function newFromDiffusionRequest(
+    DiffusionRequest $request) {
+    return self::newQueryObject(__CLASS__, $request);
+  }
+
+  final public function loadOldFilename() {
+    return $this->executeQuery();
+  }
+
+}

src/applications/diffusion/query/renamehistory/base/__init__.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/diffusion/query/base');
+
+
+phutil_require_source('DiffusionRenameHistoryQuery.php');

src/applications/diffusion/query/renamehistory/git/DiffusionGitRenameHistoryQuery.php

@@ -0,0 +1,73 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+final class DiffusionGitRenameHistoryQuery
+  extends DiffusionRenameHistoryQuery {
+
+  protected function executeQuery() {
+    $drequest = $this->getRequest();
+
+    $repository = $drequest->getRepository();
+    list($err, $stdout) = $repository->execLocalCommand(
+      'log --format=%s --follow --find-copies-harder -M -C --summary '.
+        '%s..%s -- %s',
+      '%x20',
+      $this->getOldCommit(),
+      $drequest->getCommit(),
+      $drequest->getPath());
+
+    if ($err) {
+      return null;
+    }
+
+    $lines = explode("\n", $stdout);
+    $lines = array_map('trim', $lines);
+    $lines = array_filter($lines);
+
+    $name = null;
+    foreach ($lines as $line) {
+      list($action, $info) = explode(' ', $line, 2);
+      switch ($action) {
+        case 'rename':
+          // rename path/to/file/{old.ext => new.ext} (86%)
+          $matches = null;
+          $ok = preg_match(
+            '/^(.*){(.*) => (.*)} \([0-9%]+\)$/',
+            $info,
+            $matches);
+          if (!$ok) {
+            throw new Exception(
+              "Unparseable git log --summary line: {$line}.");
+          }
+
+          $name = $matches[1].$matches[2];
+          break;
+        case 'create':
+          // create mode 100644 <filename>
+          $this->setWasCreated(true);
+          break;
+        default:
+          // Anything else we care about?
+          break;
+      }
+    }
+
+    return $name;
+  }
+
+}

src/applications/diffusion/query/renamehistory/git/__init__.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/diffusion/query/renamehistory/base');
+
+
+phutil_require_source('DiffusionGitRenameHistoryQuery.php');

src/applications/diffusion/query/renamehistory/mercurial/DiffusionMercurialRenameHistoryQuery.php

@@ -0,0 +1,27 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+final class DiffusionMercurialRenameHistoryQuery
+  extends DiffusionRenameHistoryQuery {
+
+  protected function executeQuery() {
+    // TODO: Implement.
+    return null;
+  }
+
+}

src/applications/diffusion/query/renamehistory/mercurial/__init__.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/diffusion/query/renamehistory/base');
+
+
+phutil_require_source('DiffusionMercurialRenameHistoryQuery.php');

src/applications/diffusion/query/renamehistory/svn/DiffusionSvnRenameHistoryQuery.php

@@ -0,0 +1,27 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+final class DiffusionSvnRenameHistoryQuery
+  extends DiffusionRenameHistoryQuery {
+
+  protected function executeQuery() {
+    // TODO: Implement.
+    return null;
+  }
+
+}

src/applications/diffusion/query/renamehistory/svn/__init__.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/diffusion/query/renamehistory/base');
+
+
+phutil_require_source('DiffusionSvnRenameHistoryQuery.php');