Move Differential's simple fields to the extensible field schema

Summary:
Differential has a bunch of display-only fields, implement them all as field
specifications instead of hard-coded fields.

Also add some more documentation and fix redundant string constants in blame
rev/revert plan fields.

Test Plan: Viewed, edited, and hit conduit for revisions.
Reviewed By: jungejason
Reviewers: jungejason, tuomaspelkonen, aran
CC: aran, jungejason, epriestley
Differential Revision: 807

src/__phutil_library_map__.php

@@ -133,6 +133,7 @@ phutil_register_library_map(array(
     'DatabaseConfigurationProvider' => 'applications/base/storage/configuration',
     'DifferentialAction' => 'applications/differential/constants/action',
     'DifferentialAddCommentView' => 'applications/differential/view/addcomment',
+    'DifferentialApplyPatchFieldSpecification' => 'applications/differential/field/specification/applypatch',
     'DifferentialAuxiliaryField' => 'applications/differential/storage/auxiliaryfield',
     'DifferentialBlameRevisionFieldSpecification' => 'applications/differential/field/specification/blamerev',
     'DifferentialCCWelcomeMail' => 'applications/differential/mail/ccwelcome',
@@ -162,18 +163,23 @@ phutil_register_library_map(array(
     'DifferentialDiffTableOfContentsView' => 'applications/differential/view/difftableofcontents',
     'DifferentialDiffViewController' => 'applications/differential/controller/diffview',
     'DifferentialExceptionMail' => 'applications/differential/mail/exception',
+    'DifferentialExportPatchFieldSpecification' => 'applications/differential/field/specification/exportpatch',
+    'DifferentialFieldDataNotAvailableException' => 'applications/differential/field/exception/notavailable',
     'DifferentialFieldSelector' => 'applications/differential/field/selector/base',
     'DifferentialFieldSpecification' => 'applications/differential/field/specification/base',
     'DifferentialFieldSpecificationIncompleteException' => 'applications/differential/field/exception/incomplete',
     'DifferentialFieldValidationException' => 'applications/differential/field/exception/validation',
+    'DifferentialHostFieldSpecification' => 'applications/differential/field/specification/host',
     'DifferentialHunk' => 'applications/differential/storage/hunk',
     'DifferentialInlineComment' => 'applications/differential/storage/inlinecomment',
     'DifferentialInlineCommentEditController' => 'applications/differential/controller/inlinecommentedit',
     'DifferentialInlineCommentPreviewController' => 'applications/differential/controller/inlinecommentpreview',
     'DifferentialInlineCommentView' => 'applications/differential/view/inlinecomment',
+    'DifferentialLinesFieldSpecification' => 'applications/differential/field/specification/lines',
     'DifferentialLintStatus' => 'applications/differential/constants/lintstatus',
     'DifferentialMail' => 'applications/differential/mail/base',
     'DifferentialNewDiffMail' => 'applications/differential/mail/newdiff',
+    'DifferentialPathFieldSpecification' => 'applications/differential/field/specification/path',
     'DifferentialPrimaryPaneView' => 'applications/differential/view/primarypane',
     'DifferentialReplyHandler' => 'applications/differential/replyhandler',
     'DifferentialRevertPlanFieldSpecification' => 'applications/differential/field/specification/revertplan',
@@ -775,6 +781,7 @@ phutil_register_library_map(array(
     'DarkConsoleServicesPlugin' => 'DarkConsolePlugin',
     'DarkConsoleXHProfPlugin' => 'DarkConsolePlugin',
     'DifferentialAddCommentView' => 'AphrontView',
+    'DifferentialApplyPatchFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialAuxiliaryField' => 'DifferentialDAO',
     'DifferentialBlameRevisionFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialCCWelcomeMail' => 'DifferentialReviewRequestMail',
@@ -796,12 +803,16 @@ phutil_register_library_map(array(
     'DifferentialDiffTableOfContentsView' => 'AphrontView',
     'DifferentialDiffViewController' => 'DifferentialController',
     'DifferentialExceptionMail' => 'DifferentialMail',
+    'DifferentialExportPatchFieldSpecification' => 'DifferentialFieldSpecification',
+    'DifferentialHostFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialHunk' => 'DifferentialDAO',
     'DifferentialInlineComment' => 'DifferentialDAO',
     'DifferentialInlineCommentEditController' => 'DifferentialController',
     'DifferentialInlineCommentPreviewController' => 'DifferentialController',
     'DifferentialInlineCommentView' => 'AphrontView',
+    'DifferentialLinesFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialNewDiffMail' => 'DifferentialReviewRequestMail',
+    'DifferentialPathFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialPrimaryPaneView' => 'AphrontView',
     'DifferentialReplyHandler' => 'PhabricatorMailReplyHandler',
     'DifferentialRevertPlanFieldSpecification' => 'DifferentialFieldSpecification',

src/applications/conduit/method/differential/getrevision/ConduitAPI_differential_getrevision_Method.php

@@ -116,7 +116,7 @@ class ConduitAPI_differential_getrevision_Method extends ConduitAPIMethod {
       $revision,
       $aux_fields);
 
-    return mpull($aux_fields, 'getValueForConduit', 'getStorageKey');
+    return mpull($aux_fields, 'getValueForConduit', 'getKeyForConduit');
   }
 
 }

src/applications/differential/controller/revisionview/DifferentialRevisionViewController.php

@@ -43,8 +43,6 @@ class DifferentialRevisionViewController extends DifferentialController {
         "This revision has no diffs. Something has gone quite wrong.");
     }
 
-    $aux_fields = $this->loadAuxiliaryFields($revision);
-
     $diff_vs = $request->getInt('vs');
 
     $target = end($diffs);
@@ -60,6 +58,11 @@ class DifferentialRevisionViewController extends DifferentialController {
       $diff_vs = null;
     }
 
+    $aux_fields = $this->loadAuxiliaryFields($revision);
+    foreach ($aux_fields as $aux_field) {
+      $aux_field->setDiff($target);
+    }
+
     list($changesets, $vs_map, $rendering_references) =
       $this->loadChangesetsAndVsMap($diffs, $diff_vs, $target);
 
@@ -336,17 +339,6 @@ class DifferentialRevisionViewController extends DifferentialController {
         $handles,
         $revision->getCCPHIDs()));
 
-    $host = $diff->getSourceMachine();
-    if ($host) {
-      $properties['Host'] = phutil_escape_html($host);
-    }
-
-    $path = $diff->getSourcePath();
-    if ($path) {
-      $branch = $diff->getBranch() ? ' ('.$diff->getBranch().')' : '';
-      $properties['Path'] = phutil_escape_html("{$path} {$branch}");
-    }
-
     $lstar = DifferentialRevisionUpdateHistoryView::renderDiffLintStar($diff);
     $lmsg = DifferentialRevisionUpdateHistoryView::getDiffLintMessage($diff);
     $ldata = idx($diff_properties, 'arc:lint');
@@ -474,18 +466,12 @@ class DifferentialRevisionViewController extends DifferentialController {
       $properties['Commits'] = implode('<br />', $links);
     }
 
-    $properties['Lines'] = number_format($diff->getLineCount());
     $arcanist_phid = $diff->getArcanistProjectPHID();
     if ($arcanist_phid) {
       $properties['Arcanist Project'] = phutil_escape_html(
         $handles[$arcanist_phid]->getName());
     }
 
-    $properties['Apply Patch'] =
-      '<tt>arc patch D'.$revision->getID().'</tt>';
-    $properties['Export Patch'] =
-      '<tt>arc export --revision '.$revision->getID().'</tt>';
-
     return $properties;
   }
 

src/applications/differential/field/exception/incomplete/DifferentialFieldSpecificationIncompleteException.php

@@ -16,7 +16,8 @@
  * limitations under the License.
  */
 
-class DifferentialFieldSpecificationIncompleteException extends Exception {
+final class DifferentialFieldSpecificationIncompleteException
+  extends Exception {
 
   public function __construct(DifferentialFieldSpecification $spec) {
     $key = $spec->getStorageKey();

src/applications/differential/field/exception/notavailable/DifferentialFieldDataNotAvailableException.php

@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * Copyright 2011 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 DifferentialFieldDataNotAvailableException extends Exception {
+
+  public function __construct(DifferentialFieldSpecification $spec) {
+    $key = $spec->getStorageKey();
+    $class = get_class($spec);
+
+    parent::__construct(
+      "Differential field specification for '{$key}' (of class '{$class}') is ".
+      "attempting to access data which is not available in this context.");
+  }
+
+}

src/applications/differential/field/exception/notavailable/__init__.php

@@ -0,0 +1,10 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+
+phutil_require_source('DifferentialFieldDataNotAvailableException.php');

src/applications/differential/field/selector/default/DifferentialDefaultFieldSelector.php

@@ -20,7 +20,13 @@ final class DifferentialDefaultFieldSelector
   extends DifferentialFieldSelector {
 
   public function getFieldSpecifications() {
-    return array();
+    return array(
+      new DifferentialHostFieldSpecification(),
+      new DifferentialPathFieldSpecification(),
+      new DifferentialLinesFieldSpecification(),
+      new DifferentialApplyPatchFieldSpecification(),
+      new DifferentialExportPatchFieldSpecification(),
+    );
   }
 
 }

src/applications/differential/field/selector/default/__init__.php

@@ -7,6 +7,11 @@
 
 
 phutil_require_module('phabricator', 'applications/differential/field/selector/base');
+phutil_require_module('phabricator', 'applications/differential/field/specification/applypatch');
+phutil_require_module('phabricator', 'applications/differential/field/specification/exportpatch');
+phutil_require_module('phabricator', 'applications/differential/field/specification/host');
+phutil_require_module('phabricator', 'applications/differential/field/specification/lines');
+phutil_require_module('phabricator', 'applications/differential/field/specification/path');
 
 
 phutil_require_source('DifferentialDefaultFieldSelector.php');

src/applications/differential/field/specification/applypatch/DifferentialApplyPatchFieldSpecification.php

@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * Copyright 2011 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 DifferentialApplyPatchFieldSpecification
+  extends DifferentialFieldSpecification {
+
+  public function shouldAppearOnRevisionView() {
+    return true;
+  }
+
+  public function renderLabelForRevisionView() {
+    return 'Apply Patch:';
+  }
+
+  public function renderValueForRevisionView() {
+    $revision = $this->getRevision();
+    return '<tt>arc patch D'.$revision->getID().'</tt>';
+  }
+
+}

src/applications/differential/field/specification/applypatch/__init__.php

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

src/applications/differential/field/specification/base/DifferentialFieldSpecification.php

@@ -28,52 +28,79 @@
  * @task edit Extending the Revision Edit Interface
  * @task view Extending the Revision View Interface
  * @task conduit Extending the Conduit View Interface
+ * @task context Contextual Data
  */
 abstract class DifferentialFieldSpecification {
 
+  private $revision;
+  private $diff;
+
 
 /* -(  Storage  )------------------------------------------------------------ */
 
 
   /**
    * Return a unique string used to key storage of this field's value, like
-   * "mycompany.fieldname" or similar.
+   * "mycompany.fieldname" or similar. You can return null (the default) to
+   * indicate that this field does not use any storage. This is appropriate for
+   * display fields, like @{class:DifferentialLinesFieldSpecification}. If you
+   * implement this, you must also implement @{method:getValueForStorage} and
+   * @{method:setValueFromStorage}.
    *
-   * @return string Unique key which identifies this field in auxiliary field
+   * @return string|null  Unique key which identifies this field in auxiliary
-   *                storage. Maximum length is 32.
+   *                      field storage. Maximum length is 32. Alternatively,
-   * @group storage
+   *                      null (default) to indicate that this field does not
+   *                      use auxiliary field storage.
+   * @task storage
    */
-  abstract public function getStorageKey();
+  public function getStorageKey() {
+    return null;
+  }
 
 
   /**
    * Return a serialized representation of the field value, appropriate for
-   * storing in auxiliary field storage.
+   * storing in auxiliary field storage. You must implement this method if
+   * you implement @{method:getStorageKey}.
    *
    * @return string Serialized field value.
-   * @group storage
+   * @task storage
    */
-  abstract public function getValueForStorage();
+  public function getValueForStorage() {
+    throw new DifferentialFieldSpecificationIncompleteException($this);
+  }
 
 
   /**
    * Set the field's value given a serialized storage value. This is called
    * when the field is loaded; if no data is available, the value will be
-   * null.
+   * null. You must implement this method if you implement
+   * @{method:getStorageKey}.
    *
    * @param string|null Serialized field representation (from
-   *                    getValueForStorage) or null if no value has ever been
+   *                    @{method:getValueForStorage}) or null if no value has
-   *                    stored.
+   *                    ever been stored.
    * @return this
-   * @group storage
+   * @task storage
    */
-  abstract public function setValueFromStorage($value);
+  public function setValueFromStorage($value) {
+    throw new DifferentialFieldSpecificationIncompleteException($this);
+  }
 
 
 /* -(  Extending the Revision Edit Interface  )------------------------------ */
 
 
   /**
+   * Determine if this field should appear on the "Edit Revision" interface. If
+   * you return true from this method, you must implement
+   * @{method:setValueFromRequest}, @{method:renderEditControl} and
+   * @{method:validateField}.
+   *
+   * For a concrete example of a field which implements an edit interface, see
+   * @{class:DifferentialRevertPlanFieldSpecification}.
+   *
+   * @return bool True to indicate that this field implements an edit interface.
    * @task edit
    */
   public function shouldAppearOnEdit() {
@@ -82,6 +109,23 @@ abstract class DifferentialFieldSpecification {
 
 
   /**
+   * Set the field's value from an HTTP request. Generally, you should read
+   * the value of some field name you emitted in @{method:renderEditControl}
+   * and save it into the object, e.g.:
+   *
+   *   $this->value = $request->getStr('my-custom-field');
+   *
+   * If you have some particularly complicated field, you may need to read
+   * more data; this is why you have access to the entire request.
+   *
+   * You must implement this if you implement @{method:shouldAppearOnEdit}.
+   *
+   * You should not perform field validation here; instead, you should implement
+   * @{method:validateField}.
+   *
+   * @param AphrontRequest HTTP request representing a user submitting a form
+   *                       with this field in it.
+   * @return this
    * @task edit
    */
   public function setValueFromRequest(AphrontRequest $request) {
@@ -90,6 +134,21 @@ abstract class DifferentialFieldSpecification {
 
 
   /**
+   * Build a renderable object (generally, some @{class:AphrontFormControl})
+   * which can be appended to a @{class:AphrontFormView} and represents the
+   * interface the user sees on the "Edit Revision" screen when interacting
+   * with this field.
+   *
+   * For example:
+   *
+   *   return id(new AphrontFormTextControl())
+   *     ->setLabel('Custom Field')
+   *     ->setName('my-custom-key')
+   *     ->setValue($this->value);
+   *
+   * You must implement this if you implement @{method:shouldAppearOnEdit}.
+   *
+   * @return AphrontView|string Something renderable.
    * @task edit
    */
   public function renderEditControl() {
@@ -98,10 +157,19 @@ abstract class DifferentialFieldSpecification {
 
 
   /**
+   * This method will be called after @{method:setValueFromRequest} but before
+   * the field is saved. It gives you an opportunity to inspect the field value
+   * and throw a @{class:DifferentialFieldValidationException} if there is a
+   * problem with the value the user has provided (for example, the value the
+   * user entered is not correctly formatted).
+   *
+   * By default, fields are not validated.
+   *
+   * @return void
    * @task edit
    */
   public function validateField() {
-    throw new DifferentialFieldSpecificationIncompleteException($this);
+    return;
   }
 
 
@@ -149,4 +217,54 @@ abstract class DifferentialFieldSpecification {
     throw new DifferentialFieldSpecificationIncompleteException($this);
   }
 
+  /**
+   * @task conduit
+   */
+  public function getKeyForConduit() {
+    $key = $this->getStorageKey();
+    if ($key === null) {
+      throw new DifferentialFieldSpecificationIncompleteException($this);
+    }
+    return $key;
+  }
+
+
+/* -(  Contextual Data  )---------------------------------------------------- */
+
+  /**
+   * @task context
+   */
+  final public function setRevision(DifferentialRevision $revision) {
+    $this->revision = $revision;
+    return $this;
+  }
+
+  /**
+   * @task context
+   */
+  final public function setDiff(DifferentialDiff $diff) {
+    $this->diff = $diff;
+    return $this;
+  }
+
+  /**
+   * @task context
+   */
+  final protected function getRevision() {
+    if (empty($this->revision)) {
+      throw new DifferentialFieldDataNotAvailableException($this);
+    }
+    return $this->revision;
+  }
+
+  /**
+   * @task context
+   */
+  final protected function getDiff() {
+    if (empty($this->diff)) {
+      throw new DifferentialFieldDataNotAvailableException($this);
+    }
+    return $this->diff;
+  }
+
 }

src/applications/differential/field/specification/base/__init__.php

@@ -7,6 +7,7 @@
 
 
 phutil_require_module('phabricator', 'applications/differential/field/exception/incomplete');
+phutil_require_module('phabricator', 'applications/differential/field/exception/notavailable');
 
 
 phutil_require_source('DifferentialFieldSpecification.php');

src/applications/differential/field/specification/blamerev/DifferentialBlameRevisionFieldSpecification.php

@@ -39,7 +39,7 @@ final class DifferentialBlameRevisionFieldSpecification
   }
 
   public function setValueFromRequest(AphrontRequest $request) {
-    $this->value = $request->getStr('aux:phabricator:blame-revision');
+    $this->value = $request->getStr($this->getStorageKey());
     return $this;
   }
 
@@ -47,7 +47,7 @@ final class DifferentialBlameRevisionFieldSpecification
     return id(new AphrontFormTextControl())
       ->setLabel('Blame Revision')
       ->setCaption('Revision which broke the stuff which this change fixes.')
-      ->setName('aux:phabricator:blame-revision')
+      ->setName($this->getStorageKey())
       ->setValue($this->value);
   }
 

src/applications/differential/field/specification/exportpatch/DifferentialExportPatchFieldSpecification.php

@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * Copyright 2011 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 DifferentialExportPatchFieldSpecification
+  extends DifferentialFieldSpecification {
+
+  public function shouldAppearOnRevisionView() {
+    return true;
+  }
+
+  public function renderLabelForRevisionView() {
+    return 'Export Patch:';
+  }
+
+  public function renderValueForRevisionView() {
+    $revision = $this->getRevision();
+    return '<tt>arc export --revision '.$revision->getID().'</tt>';
+  }
+
+}

src/applications/differential/field/specification/exportpatch/__init__.php

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

src/applications/differential/field/specification/host/DifferentialHostFieldSpecification.php

@@ -0,0 +1,39 @@
+<?php
+
+/*
+ * Copyright 2011 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 DifferentialHostFieldSpecification
+  extends DifferentialFieldSpecification {
+
+  public function shouldAppearOnRevisionView() {
+    return true;
+  }
+
+  public function renderLabelForRevisionView() {
+    return 'Host:';
+  }
+
+  public function renderValueForRevisionView() {
+    $diff = $this->getDiff();
+    $host = $diff->getSourceMachine();
+    if (!$host) {
+      return null;
+    }
+    return phutil_escape_html($host);
+  }
+
+}

src/applications/differential/field/specification/host/__init__.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/differential/field/specification/base');
+
+phutil_require_module('phutil', 'markup');
+
+
+phutil_require_source('DifferentialHostFieldSpecification.php');

src/applications/differential/field/specification/lines/DifferentialLinesFieldSpecification.php

@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * Copyright 2011 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 DifferentialLinesFieldSpecification
+  extends DifferentialFieldSpecification {
+
+  public function shouldAppearOnRevisionView() {
+    return true;
+  }
+
+  public function renderLabelForRevisionView() {
+    return 'Lines:';
+  }
+
+  public function renderValueForRevisionView() {
+    $diff = $this->getDiff();
+    return phutil_escape_html(number_format($diff->getLineCount()));
+  }
+
+}

src/applications/differential/field/specification/lines/__init__.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/differential/field/specification/base');
+
+phutil_require_module('phutil', 'markup');
+
+
+phutil_require_source('DifferentialLinesFieldSpecification.php');

src/applications/differential/field/specification/path/DifferentialPathFieldSpecification.php

@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * Copyright 2011 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 DifferentialPathFieldSpecification
+  extends DifferentialFieldSpecification {
+
+  public function shouldAppearOnRevisionView() {
+    return true;
+  }
+
+  public function renderLabelForRevisionView() {
+    return 'Path:';
+  }
+
+  public function renderValueForRevisionView() {
+    $diff = $this->getDiff();
+
+    $path = $diff->getSourcePath();
+    if (!$path) {
+      return null;
+    }
+
+    $branch = $diff->getBranch();
+    if ($branch) {
+      $branch = ' ('.$branch.')';
+    }
+
+    return phutil_escape_html($path.$branch);
+  }
+
+}

src/applications/differential/field/specification/path/__init__.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/differential/field/specification/base');
+
+phutil_require_module('phutil', 'markup');
+
+
+phutil_require_source('DifferentialPathFieldSpecification.php');

src/applications/differential/field/specification/revertplan/DifferentialRevertPlanFieldSpecification.php

@@ -39,14 +39,14 @@ final class DifferentialRevertPlanFieldSpecification
   }
 
   public function setValueFromRequest(AphrontRequest $request) {
-    $this->value = $request->getStr('aux:phabricator:revert-plan');
+    $this->value = $request->getStr($this->getStorageKey());
     return $this;
   }
 
   public function renderEditControl() {
     return id(new AphrontFormTextAreaControl())
       ->setLabel('Revert Plan')
-      ->setName('aux:phabricator:revert-plan')
+      ->setName($this->getStorageKey())
       ->setCaption('Special steps required to safely revert this change.')
       ->setValue($this->value);
   }

src/applications/differential/storage/auxiliaryfield/DifferentialAuxiliaryField.php

@@ -47,6 +47,7 @@ final class DifferentialAuxiliaryField extends DifferentialDAO {
     }
 
     foreach ($aux_fields as $aux_field) {
+      $aux_field->setRevision($revision);
       $key = $aux_field->getStorageKey();
       if ($key) {
         $aux_field->setValueFromStorage(idx($field_data, $key));