Allow pastes to be destroyed

Summary: Fixes T6186.

Test Plan:
  - Used `bin/remove destroy Pxxx` to destroy a paste.
  - Verified file, transactions, etc., were destroyed.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T6186

Differential Revision: https://secure.phabricator.com/D10563

src/__phutil_library_map__.php

@@ -4855,6 +4855,8 @@ phutil_register_library_map(array(
       'PhabricatorMentionableInterface',
       'PhabricatorPolicyInterface',
       'PhabricatorProjectInterface',
+      'PhabricatorDestructibleInterface',
+      'PhabricatorApplicationTransactionInterface',
     ),
     'PhabricatorPasteApplication' => 'PhabricatorApplication',
     'PhabricatorPasteCommentController' => 'PhabricatorPasteController',

src/applications/paste/storage/PhabricatorPaste.php

@@ -7,7 +7,9 @@ final class PhabricatorPaste extends PhabricatorPasteDAO
     PhabricatorFlaggableInterface,
     PhabricatorMentionableInterface,
     PhabricatorPolicyInterface,
-    PhabricatorProjectInterface {
+    PhabricatorProjectInterface,
+    PhabricatorDestructibleInterface,
+    PhabricatorApplicationTransactionInterface {
 
   protected $title;
   protected $authorPHID;
@@ -152,4 +154,40 @@ final class PhabricatorPaste extends PhabricatorPasteDAO
     return pht('The author of a paste can always view and edit it.');
   }
 
+
+/* -(  PhabricatorDestructibleInterface  )----------------------------------- */
+
+
+  public function destroyObjectPermanently(
+    PhabricatorDestructionEngine $engine) {
+
+    if ($this->filePHID) {
+      $file = id(new PhabricatorFileQuery())
+        ->setViewer(PhabricatorUser::getOmnipotentUser())
+        ->withPHIDs(array($this->filePHID))
+        ->executeOne();
+      if ($file) {
+        $engine->destroyObject($file);
+      }
+    }
+
+    $this->delete();
+  }
+
+
+/* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
+
+
+  public function getApplicationTransactionEditor() {
+    return new PhabricatorPasteEditor();
+  }
+
+  public function getApplicationTransactionObject() {
+    return $this;
+  }
+
+  public function getApplicationTransactionTemplate() {
+    return new PhabricatorPasteTransaction();
+  }
+
 }