diff --git a/resources/sql/autopatches/20160711.files.01.builtin.sql b/resources/sql/autopatches/20160711.files.01.builtin.sql
new file mode 100644
index 0000000000..d8849ec053
--- /dev/null
+++ b/resources/sql/autopatches/20160711.files.01.builtin.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_file.file
+  ADD builtinKey VARCHAR(64) COLLATE {$COLLATE_TEXT};
diff --git a/resources/sql/autopatches/20160711.files.02.builtinkey.sql b/resources/sql/autopatches/20160711.files.02.builtinkey.sql
new file mode 100644
index 0000000000..3551f6c3cd
--- /dev/null
+++ b/resources/sql/autopatches/20160711.files.02.builtinkey.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_file.file
+  ADD UNIQUE KEY `key_builtin` (builtinKey);
diff --git a/src/applications/files/query/PhabricatorFileQuery.php b/src/applications/files/query/PhabricatorFileQuery.php
index 5e1876acd6..c2ac083fea 100644
--- a/src/applications/files/query/PhabricatorFileQuery.php
+++ b/src/applications/files/query/PhabricatorFileQuery.php
@@ -1,398 +1,411 @@
 <?php
 
 final class PhabricatorFileQuery
   extends PhabricatorCursorPagedPolicyAwareQuery {
 
   private $ids;
   private $phids;
   private $authorPHIDs;
   private $explicitUploads;
   private $transforms;
   private $dateCreatedAfter;
   private $dateCreatedBefore;
   private $contentHashes;
   private $minLength;
   private $maxLength;
   private $names;
   private $isPartial;
   private $needTransforms;
+  private $builtinKeys;
 
   public function withIDs(array $ids) {
     $this->ids = $ids;
     return $this;
   }
 
   public function withPHIDs(array $phids) {
     $this->phids = $phids;
     return $this;
   }
 
   public function withAuthorPHIDs(array $phids) {
     $this->authorPHIDs = $phids;
     return $this;
   }
 
   public function withDateCreatedBefore($date_created_before) {
     $this->dateCreatedBefore = $date_created_before;
     return $this;
   }
 
   public function withDateCreatedAfter($date_created_after) {
     $this->dateCreatedAfter = $date_created_after;
     return $this;
   }
 
   public function withContentHashes(array $content_hashes) {
     $this->contentHashes = $content_hashes;
     return $this;
   }
 
+  public function withBuiltinKeys(array $keys) {
+    $this->builtinKeys = $keys;
+    return $this;
+  }
+
   /**
    * Select files which are transformations of some other file. For example,
    * you can use this query to find previously generated thumbnails of an image
    * file.
    *
    * As a parameter, provide a list of transformation specifications. Each
    * specification is a dictionary with the keys `originalPHID` and `transform`.
    * The `originalPHID` is the PHID of the original file (the file which was
    * transformed) and the `transform` is the name of the transform to query
    * for. If you pass `true` as the `transform`, all transformations of the
    * file will be selected.
    *
    * For example:
    *
    *   array(
    *     array(
    *       'originalPHID' => 'PHID-FILE-aaaa',
    *       'transform'    => 'sepia',
    *     ),
    *     array(
    *       'originalPHID' => 'PHID-FILE-bbbb',
    *       'transform'    => true,
    *     ),
    *   )
    *
    * This selects the `"sepia"` transformation of the file with PHID
    * `PHID-FILE-aaaa` and all transformations of the file with PHID
    * `PHID-FILE-bbbb`.
    *
    * @param list<dict>  List of transform specifications, described above.
    * @return this
    */
   public function withTransforms(array $specs) {
     foreach ($specs as $spec) {
       if (!is_array($spec) ||
           empty($spec['originalPHID']) ||
           empty($spec['transform'])) {
         throw new Exception(
           pht(
             "Transform specification must be a dictionary with keys ".
             "'%s' and '%s'!",
             'originalPHID',
             'transform'));
       }
     }
 
     $this->transforms = $specs;
     return $this;
   }
 
   public function withLengthBetween($min, $max) {
     $this->minLength = $min;
     $this->maxLength = $max;
     return $this;
   }
 
   public function withNames(array $names) {
     $this->names = $names;
     return $this;
   }
 
   public function withIsPartial($partial) {
     $this->isPartial = $partial;
     return $this;
   }
 
   public function showOnlyExplicitUploads($explicit_uploads) {
     $this->explicitUploads = $explicit_uploads;
     return $this;
   }
 
   public function needTransforms(array $transforms) {
     $this->needTransforms = $transforms;
     return $this;
   }
 
   public function newResultObject() {
     return new PhabricatorFile();
   }
 
   protected function loadPage() {
     $files = $this->loadStandardPage(new PhabricatorFile());
 
     if (!$files) {
       return $files;
     }
 
     $viewer = $this->getViewer();
     $is_omnipotent = $viewer->isOmnipotent();
 
     // We need to load attached objects to perform policy checks for files.
     // First, load the edges.
 
     $edge_type = PhabricatorFileHasObjectEdgeType::EDGECONST;
     $file_phids = mpull($files, 'getPHID');
     $edges = id(new PhabricatorEdgeQuery())
       ->withSourcePHIDs($file_phids)
       ->withEdgeTypes(array($edge_type))
       ->execute();
 
     $object_phids = array();
     foreach ($files as $file) {
       $phids = array_keys($edges[$file->getPHID()][$edge_type]);
       $file->attachObjectPHIDs($phids);
 
       if ($file->getIsProfileImage()) {
         // If this is a profile image, don't bother loading related files.
         // It will always be visible, and we can get into trouble if we try
         // to load objects and end up stuck in a cycle. See T8478.
         continue;
       }
 
       if ($is_omnipotent) {
         // If the viewer is omnipotent, we don't need to load the associated
         // objects either since they can certainly see the object. Skipping
         // this can improve performance and prevent cycles.
         continue;
       }
 
       foreach ($phids as $phid) {
         $object_phids[$phid] = true;
       }
     }
 
     // If this file is a transform of another file, load that file too. If you
     // can see the original file, you can see the thumbnail.
 
     // TODO: It might be nice to put this directly on PhabricatorFile and remove
     // the PhabricatorTransformedFile table, which would be a little simpler.
 
     $xforms = id(new PhabricatorTransformedFile())->loadAllWhere(
       'transformedPHID IN (%Ls)',
       $file_phids);
     $xform_phids = mpull($xforms, 'getOriginalPHID', 'getTransformedPHID');
     foreach ($xform_phids as $derived_phid => $original_phid) {
       $object_phids[$original_phid] = true;
     }
 
     $object_phids = array_keys($object_phids);
 
     // Now, load the objects.
 
     $objects = array();
     if ($object_phids) {
       // NOTE: We're explicitly turning policy exceptions off, since the rule
       // here is "you can see the file if you can see ANY associated object".
       // Without this explicit flag, we'll incorrectly throw unless you can
       // see ALL associated objects.
 
       $objects = id(new PhabricatorObjectQuery())
         ->setParentQuery($this)
         ->setViewer($this->getViewer())
         ->withPHIDs($object_phids)
         ->setRaisePolicyExceptions(false)
         ->execute();
       $objects = mpull($objects, null, 'getPHID');
     }
 
     foreach ($files as $file) {
       $file_objects = array_select_keys($objects, $file->getObjectPHIDs());
       $file->attachObjects($file_objects);
     }
 
     foreach ($files as $key => $file) {
       $original_phid = idx($xform_phids, $file->getPHID());
       if ($original_phid == PhabricatorPHIDConstants::PHID_VOID) {
         // This is a special case for builtin files, which are handled
         // oddly.
         $original = null;
       } else if ($original_phid) {
         $original = idx($objects, $original_phid);
         if (!$original) {
           // If the viewer can't see the original file, also prevent them from
           // seeing the transformed file.
           $this->didRejectResult($file);
           unset($files[$key]);
           continue;
         }
       } else {
         $original = null;
       }
       $file->attachOriginalFile($original);
     }
 
     return $files;
   }
 
   protected function didFilterPage(array $files) {
     $xform_keys = $this->needTransforms;
     if ($xform_keys !== null) {
       $xforms = id(new PhabricatorTransformedFile())->loadAllWhere(
         'originalPHID IN (%Ls) AND transform IN (%Ls)',
         mpull($files, 'getPHID'),
         $xform_keys);
 
       if ($xforms) {
         $xfiles = id(new PhabricatorFile())->loadAllWhere(
           'phid IN (%Ls)',
           mpull($xforms, 'getTransformedPHID'));
         $xfiles = mpull($xfiles, null, 'getPHID');
       }
 
       $xform_map = array();
       foreach ($xforms as $xform) {
         $xfile = idx($xfiles, $xform->getTransformedPHID());
         if (!$xfile) {
           continue;
         }
         $original_phid = $xform->getOriginalPHID();
         $xform_key = $xform->getTransform();
         $xform_map[$original_phid][$xform_key] = $xfile;
       }
 
       $default_xforms = array_fill_keys($xform_keys, null);
 
       foreach ($files as $file) {
         $file_xforms = idx($xform_map, $file->getPHID(), array());
         $file_xforms += $default_xforms;
         $file->attachTransforms($file_xforms);
       }
     }
 
     return $files;
   }
 
   protected function buildJoinClauseParts(AphrontDatabaseConnection $conn) {
     $joins = parent::buildJoinClauseParts($conn);
 
     if ($this->transforms) {
       $joins[] = qsprintf(
         $conn,
         'JOIN %T t ON t.transformedPHID = f.phid',
         id(new PhabricatorTransformedFile())->getTableName());
     }
 
     return $joins;
   }
 
   protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
     $where = parent::buildWhereClauseParts($conn);
 
     if ($this->ids !== null) {
       $where[] = qsprintf(
         $conn,
         'f.id IN (%Ld)',
         $this->ids);
     }
 
     if ($this->phids !== null) {
       $where[] = qsprintf(
         $conn,
         'f.phid IN (%Ls)',
         $this->phids);
     }
 
     if ($this->authorPHIDs !== null) {
       $where[] = qsprintf(
         $conn,
         'f.authorPHID IN (%Ls)',
         $this->authorPHIDs);
     }
 
     if ($this->explicitUploads !== null) {
       $where[] = qsprintf(
         $conn,
         'f.isExplicitUpload = %d',
         (int)$this->explicitUploads);
     }
 
     if ($this->transforms !== null) {
       $clauses = array();
       foreach ($this->transforms as $transform) {
         if ($transform['transform'] === true) {
           $clauses[] = qsprintf(
             $conn,
             '(t.originalPHID = %s)',
             $transform['originalPHID']);
         } else {
           $clauses[] = qsprintf(
             $conn,
             '(t.originalPHID = %s AND t.transform = %s)',
             $transform['originalPHID'],
             $transform['transform']);
         }
       }
       $where[] = qsprintf($conn, '(%Q)', implode(') OR (', $clauses));
     }
 
     if ($this->dateCreatedAfter !== null) {
       $where[] = qsprintf(
         $conn,
         'f.dateCreated >= %d',
         $this->dateCreatedAfter);
     }
 
     if ($this->dateCreatedBefore !== null) {
       $where[] = qsprintf(
         $conn,
         'f.dateCreated <= %d',
         $this->dateCreatedBefore);
     }
 
     if ($this->contentHashes !== null) {
       $where[] = qsprintf(
         $conn,
         'f.contentHash IN (%Ls)',
         $this->contentHashes);
     }
 
     if ($this->minLength !== null) {
       $where[] = qsprintf(
         $conn,
         'byteSize >= %d',
         $this->minLength);
     }
 
     if ($this->maxLength !== null) {
       $where[] = qsprintf(
         $conn,
         'byteSize <= %d',
         $this->maxLength);
     }
 
     if ($this->names !== null) {
       $where[] = qsprintf(
         $conn,
         'name in (%Ls)',
         $this->names);
     }
 
     if ($this->isPartial !== null) {
       $where[] = qsprintf(
         $conn,
         'isPartial = %d',
         (int)$this->isPartial);
     }
 
+    if ($this->builtinKeys !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'builtinKey IN (%Ls)',
+        $this->builtinKeys);
+    }
+
     return $where;
   }
 
   protected function getPrimaryTableAlias() {
     return 'f';
   }
 
   public function getQueryApplicationClass() {
     return 'PhabricatorFilesApplication';
   }
 
 }
diff --git a/src/applications/files/storage/PhabricatorFile.php b/src/applications/files/storage/PhabricatorFile.php
index 7e8f4b18fc..8d81c3ae98 100644
--- a/src/applications/files/storage/PhabricatorFile.php
+++ b/src/applications/files/storage/PhabricatorFile.php
@@ -1,1455 +1,1463 @@
 <?php
 
 /**
  * Parameters
  * ==========
  *
  * When creating a new file using a method like @{method:newFromFileData}, these
  * parameters are supported:
  *
  *   | name | Human readable filename.
  *   | authorPHID | User PHID of uploader.
  *   | ttl | Temporary file lifetime, in seconds.
  *   | viewPolicy | File visibility policy.
  *   | isExplicitUpload | Used to show users files they explicitly uploaded.
  *   | canCDN | Allows the file to be cached and delivered over a CDN.
  *   | mime-type | Optional, explicit file MIME type.
  *   | builtin | Optional filename, identifies this as a builtin.
  *
  */
 final class PhabricatorFile extends PhabricatorFileDAO
   implements
     PhabricatorApplicationTransactionInterface,
     PhabricatorTokenReceiverInterface,
     PhabricatorSubscribableInterface,
     PhabricatorFlaggableInterface,
     PhabricatorPolicyInterface,
     PhabricatorDestructibleInterface {
 
   const METADATA_IMAGE_WIDTH  = 'width';
   const METADATA_IMAGE_HEIGHT = 'height';
   const METADATA_CAN_CDN = 'canCDN';
   const METADATA_BUILTIN = 'builtin';
   const METADATA_PARTIAL = 'partial';
   const METADATA_PROFILE = 'profile';
   const METADATA_STORAGE = 'storage';
 
   protected $name;
   protected $mimeType;
   protected $byteSize;
   protected $authorPHID;
   protected $secretKey;
   protected $contentHash;
   protected $metadata = array();
   protected $mailKey;
+  protected $builtinKey;
 
   protected $storageEngine;
   protected $storageFormat;
   protected $storageHandle;
 
   protected $ttl;
   protected $isExplicitUpload = 1;
   protected $viewPolicy = PhabricatorPolicies::POLICY_USER;
   protected $isPartial = 0;
 
   private $objects = self::ATTACHABLE;
   private $objectPHIDs = self::ATTACHABLE;
   private $originalFile = self::ATTACHABLE;
   private $transforms = self::ATTACHABLE;
 
   public static function initializeNewFile() {
     $app = id(new PhabricatorApplicationQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withClasses(array('PhabricatorFilesApplication'))
       ->executeOne();
 
     $view_policy = $app->getPolicy(
       FilesDefaultViewCapability::CAPABILITY);
 
     return id(new PhabricatorFile())
       ->setViewPolicy($view_policy)
       ->setIsPartial(0)
       ->attachOriginalFile(null)
       ->attachObjects(array())
       ->attachObjectPHIDs(array());
   }
 
   protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_SERIALIZATION => array(
         'metadata' => self::SERIALIZATION_JSON,
       ),
       self::CONFIG_COLUMN_SCHEMA => array(
         'name' => 'text255?',
         'mimeType' => 'text255?',
         'byteSize' => 'uint64',
         'storageEngine' => 'text32',
         'storageFormat' => 'text32',
         'storageHandle' => 'text255',
         'authorPHID' => 'phid?',
         'secretKey' => 'bytes20?',
         'contentHash' => 'bytes40?',
         'ttl' => 'epoch?',
         'isExplicitUpload' => 'bool?',
         'mailKey' => 'bytes20',
         'isPartial' => 'bool',
+        'builtinKey' => 'text64?',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'key_phid' => null,
         'phid' => array(
           'columns' => array('phid'),
           'unique' => true,
         ),
         'authorPHID' => array(
           'columns' => array('authorPHID'),
         ),
         'contentHash' => array(
           'columns' => array('contentHash'),
         ),
         'key_ttl' => array(
           'columns' => array('ttl'),
         ),
         'key_dateCreated' => array(
           'columns' => array('dateCreated'),
         ),
         'key_partial' => array(
           'columns' => array('authorPHID', 'isPartial'),
         ),
+        'key_builtin' => array(
+          'columns' => array('builtinKey'),
+          'unique' => true,
+        ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       PhabricatorFileFilePHIDType::TYPECONST);
   }
 
   public function save() {
     if (!$this->getSecretKey()) {
       $this->setSecretKey($this->generateSecretKey());
     }
     if (!$this->getMailKey()) {
       $this->setMailKey(Filesystem::readRandomCharacters(20));
     }
     return parent::save();
   }
 
   public function getMonogram() {
     return 'F'.$this->getID();
   }
 
   public function scrambleSecret() {
     return $this->setSecretKey($this->generateSecretKey());
   }
 
   public static function readUploadedFileData($spec) {
     if (!$spec) {
       throw new Exception(pht('No file was uploaded!'));
     }
 
     $err = idx($spec, 'error');
     if ($err) {
       throw new PhabricatorFileUploadException($err);
     }
 
     $tmp_name = idx($spec, 'tmp_name');
     $is_valid = @is_uploaded_file($tmp_name);
     if (!$is_valid) {
       throw new Exception(pht('File is not an uploaded file.'));
     }
 
     $file_data = Filesystem::readFile($tmp_name);
     $file_size = idx($spec, 'size');
 
     if (strlen($file_data) != $file_size) {
       throw new Exception(pht('File size disagrees with uploaded size.'));
     }
 
     return $file_data;
   }
 
   public static function newFromPHPUpload($spec, array $params = array()) {
     $file_data = self::readUploadedFileData($spec);
 
     $file_name = nonempty(
       idx($params, 'name'),
       idx($spec,   'name'));
     $params = array(
       'name' => $file_name,
     ) + $params;
 
     return self::newFromFileData($file_data, $params);
   }
 
   public static function newFromXHRUpload($data, array $params = array()) {
     return self::newFromFileData($data, $params);
   }
 
 
   /**
    * Given a block of data, try to load an existing file with the same content
    * if one exists. If it does not, build a new file.
    *
    * This method is generally used when we have some piece of semi-trusted data
    * like a diff or a file from a repository that we want to show to the user.
    * We can't just dump it out because it may be dangerous for any number of
    * reasons; instead, we need to serve it through the File abstraction so it
    * ends up on the CDN domain if one is configured and so on. However, if we
    * simply wrote a new file every time we'd potentially end up with a lot
    * of redundant data in file storage.
    *
    * To solve these problems, we use file storage as a cache and reuse the
    * same file again if we've previously written it.
    *
    * NOTE: This method unguards writes.
    *
    * @param string  Raw file data.
    * @param dict    Dictionary of file information.
    */
   public static function buildFromFileDataOrHash(
     $data,
     array $params = array()) {
 
     $file = id(new PhabricatorFile())->loadOneWhere(
       'name = %s AND contentHash = %s LIMIT 1',
       idx($params, 'name'),
       self::hashFileContent($data));
 
     if (!$file) {
       $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
       $file = self::newFromFileData($data, $params);
       unset($unguarded);
     }
 
     return $file;
   }
 
   public static function newFileFromContentHash($hash, array $params) {
     // Check to see if a file with same contentHash exist
     $file = id(new PhabricatorFile())->loadOneWhere(
       'contentHash = %s LIMIT 1',
       $hash);
 
     if ($file) {
       $copy_of_storage_engine = $file->getStorageEngine();
       $copy_of_storage_handle = $file->getStorageHandle();
       $copy_of_storage_format = $file->getStorageFormat();
       $copy_of_storage_properties = $file->getStorageProperties();
       $copy_of_byte_size = $file->getByteSize();
       $copy_of_mime_type = $file->getMimeType();
 
       $new_file = self::initializeNewFile();
 
       $new_file->setByteSize($copy_of_byte_size);
 
       $new_file->setContentHash($hash);
       $new_file->setStorageEngine($copy_of_storage_engine);
       $new_file->setStorageHandle($copy_of_storage_handle);
       $new_file->setStorageFormat($copy_of_storage_format);
       $new_file->setStorageProperties($copy_of_storage_properties);
       $new_file->setMimeType($copy_of_mime_type);
       $new_file->copyDimensions($file);
 
       $new_file->readPropertiesFromParameters($params);
 
       $new_file->save();
 
       return $new_file;
     }
 
     return $file;
   }
 
   public static function newChunkedFile(
     PhabricatorFileStorageEngine $engine,
     $length,
     array $params) {
 
     $file = self::initializeNewFile();
 
     $file->setByteSize($length);
 
     // NOTE: Once we receive the first chunk, we'll detect its MIME type and
     // update the parent file. This matters for large media files like video.
     $file->setMimeType('application/octet-stream');
 
     $chunked_hash = idx($params, 'chunkedHash');
     if ($chunked_hash) {
       $file->setContentHash($chunked_hash);
     } else {
       // See PhabricatorChunkedFileStorageEngine::getChunkedHash() for some
       // discussion of this.
       $seed = Filesystem::readRandomBytes(64);
       $hash = PhabricatorChunkedFileStorageEngine::getChunkedHashForInput(
         $seed);
       $file->setContentHash($hash);
     }
 
     $file->setStorageEngine($engine->getEngineIdentifier());
     $file->setStorageHandle(PhabricatorFileChunk::newChunkHandle());
 
     // Chunked files are always stored raw because they do not actually store
     // data. The chunks do, and can be individually formatted.
     $file->setStorageFormat(PhabricatorFileRawStorageFormat::FORMATKEY);
 
     $file->setIsPartial(1);
 
     $file->readPropertiesFromParameters($params);
 
     return $file;
   }
 
   private static function buildFromFileData($data, array $params = array()) {
 
     if (isset($params['storageEngines'])) {
       $engines = $params['storageEngines'];
     } else {
       $size = strlen($data);
       $engines = PhabricatorFileStorageEngine::loadStorageEngines($size);
 
       if (!$engines) {
         throw new Exception(
           pht(
             'No configured storage engine can store this file. See '.
             '"Configuring File Storage" in the documentation for '.
             'information on configuring storage engines.'));
       }
     }
 
     assert_instances_of($engines, 'PhabricatorFileStorageEngine');
     if (!$engines) {
       throw new Exception(pht('No valid storage engines are available!'));
     }
 
     $file = self::initializeNewFile();
 
     $aes_type = PhabricatorFileAES256StorageFormat::FORMATKEY;
     $has_aes = PhabricatorKeyring::getDefaultKeyName($aes_type);
     if ($has_aes !== null) {
       $default_key = PhabricatorFileAES256StorageFormat::FORMATKEY;
     } else {
       $default_key = PhabricatorFileRawStorageFormat::FORMATKEY;
     }
     $key = idx($params, 'format', $default_key);
 
     // Callers can pass in an object explicitly instead of a key. This is
     // primarily useful for unit tests.
     if ($key instanceof PhabricatorFileStorageFormat) {
       $format = clone $key;
     } else {
       $format = clone PhabricatorFileStorageFormat::requireFormat($key);
     }
 
     $format->setFile($file);
 
     $properties = $format->newStorageProperties();
     $file->setStorageFormat($format->getStorageFormatKey());
     $file->setStorageProperties($properties);
 
     $data_handle = null;
     $engine_identifier = null;
     $exceptions = array();
     foreach ($engines as $engine) {
       $engine_class = get_class($engine);
       try {
         list($engine_identifier, $data_handle) = $file->writeToEngine(
           $engine,
           $data,
           $params);
 
         // We stored the file somewhere so stop trying to write it to other
         // places.
         break;
       } catch (PhabricatorFileStorageConfigurationException $ex) {
         // If an engine is outright misconfigured (or misimplemented), raise
         // that immediately since it probably needs attention.
         throw $ex;
       } catch (Exception $ex) {
         phlog($ex);
 
         // If an engine doesn't work, keep trying all the other valid engines
         // in case something else works.
         $exceptions[$engine_class] = $ex;
       }
     }
 
     if (!$data_handle) {
       throw new PhutilAggregateException(
         pht('All storage engines failed to write file:'),
         $exceptions);
     }
 
     $file->setByteSize(strlen($data));
     $file->setContentHash(self::hashFileContent($data));
 
     $file->setStorageEngine($engine_identifier);
     $file->setStorageHandle($data_handle);
 
     $file->readPropertiesFromParameters($params);
 
     if (!$file->getMimeType()) {
       $tmp = new TempFile();
       Filesystem::writeFile($tmp, $data);
       $file->setMimeType(Filesystem::getMimeType($tmp));
     }
 
     try {
       $file->updateDimensions(false);
     } catch (Exception $ex) {
       // Do nothing
     }
 
     $file->save();
 
     return $file;
   }
 
   public static function newFromFileData($data, array $params = array()) {
     $hash = self::hashFileContent($data);
     $file = self::newFileFromContentHash($hash, $params);
 
     if ($file) {
       return $file;
     }
 
     return self::buildFromFileData($data, $params);
   }
 
   public function migrateToEngine(PhabricatorFileStorageEngine $engine) {
     if (!$this->getID() || !$this->getStorageHandle()) {
       throw new Exception(
         pht("You can not migrate a file which hasn't yet been saved."));
     }
 
     $data = $this->loadFileData();
     $params = array(
       'name' => $this->getName(),
     );
 
     list($new_identifier, $new_handle) = $this->writeToEngine(
       $engine,
       $data,
       $params);
 
     $old_engine = $this->instantiateStorageEngine();
     $old_identifier = $this->getStorageEngine();
     $old_handle = $this->getStorageHandle();
 
     $this->setStorageEngine($new_identifier);
     $this->setStorageHandle($new_handle);
     $this->save();
 
     $this->deleteFileDataIfUnused(
       $old_engine,
       $old_identifier,
       $old_handle);
 
     return $this;
   }
 
   public function migrateToStorageFormat(PhabricatorFileStorageFormat $format) {
     if (!$this->getID() || !$this->getStorageHandle()) {
       throw new Exception(
         pht("You can not migrate a file which hasn't yet been saved."));
     }
 
     $data = $this->loadFileData();
     $params = array(
       'name' => $this->getName(),
     );
 
     $engine = $this->instantiateStorageEngine();
     $old_handle = $this->getStorageHandle();
 
     $properties = $format->newStorageProperties();
     $this->setStorageFormat($format->getStorageFormatKey());
     $this->setStorageProperties($properties);
 
     list($identifier, $new_handle) = $this->writeToEngine(
       $engine,
       $data,
       $params);
 
     $this->setStorageHandle($new_handle);
     $this->save();
 
     $this->deleteFileDataIfUnused(
       $engine,
       $identifier,
       $old_handle);
 
     return $this;
   }
 
   public function cycleMasterStorageKey(PhabricatorFileStorageFormat $format) {
     if (!$this->getID() || !$this->getStorageHandle()) {
       throw new Exception(
         pht("You can not cycle keys for a file which hasn't yet been saved."));
     }
 
     $properties = $format->cycleStorageProperties();
     $this->setStorageProperties($properties);
     $this->save();
 
     return $this;
   }
 
   private function writeToEngine(
     PhabricatorFileStorageEngine $engine,
     $data,
     array $params) {
 
     $engine_class = get_class($engine);
 
     $key = $this->getStorageFormat();
     $format = id(clone PhabricatorFileStorageFormat::requireFormat($key))
       ->setFile($this);
 
     $data_iterator = array($data);
     $formatted_iterator = $format->newWriteIterator($data_iterator);
     $formatted_data = $this->loadDataFromIterator($formatted_iterator);
 
     $data_handle = $engine->writeFile($formatted_data, $params);
 
     if (!$data_handle || strlen($data_handle) > 255) {
       // This indicates an improperly implemented storage engine.
       throw new PhabricatorFileStorageConfigurationException(
         pht(
           "Storage engine '%s' executed %s but did not return a valid ".
           "handle ('%s') to the data: it must be nonempty and no longer ".
           "than 255 characters.",
           $engine_class,
           'writeFile()',
           $data_handle));
     }
 
     $engine_identifier = $engine->getEngineIdentifier();
     if (!$engine_identifier || strlen($engine_identifier) > 32) {
       throw new PhabricatorFileStorageConfigurationException(
         pht(
           "Storage engine '%s' returned an improper engine identifier '{%s}': ".
           "it must be nonempty and no longer than 32 characters.",
           $engine_class,
           $engine_identifier));
     }
 
     return array($engine_identifier, $data_handle);
   }
 
 
   /**
    * Download a remote resource over HTTP and save the response body as a file.
    *
    * This method respects `security.outbound-blacklist`, and protects against
    * HTTP redirection (by manually following "Location" headers and verifying
    * each destination). It does not protect against DNS rebinding. See
    * discussion in T6755.
    */
   public static function newFromFileDownload($uri, array $params = array()) {
     $timeout = 5;
 
     $redirects = array();
     $current = $uri;
     while (true) {
       try {
         if (count($redirects) > 10) {
           throw new Exception(
             pht('Too many redirects trying to fetch remote URI.'));
         }
 
         $resolved = PhabricatorEnv::requireValidRemoteURIForFetch(
           $current,
           array(
             'http',
             'https',
           ));
 
         list($resolved_uri, $resolved_domain) = $resolved;
 
         $current = new PhutilURI($current);
         if ($current->getProtocol() == 'http') {
           // For HTTP, we can use a pre-resolved URI to defuse DNS rebinding.
           $fetch_uri = $resolved_uri;
           $fetch_host = $resolved_domain;
         } else {
           // For HTTPS, we can't: cURL won't verify the SSL certificate if
           // the domain has been replaced with an IP. But internal services
           // presumably will not have valid certificates for rebindable
           // domain names on attacker-controlled domains, so the DNS rebinding
           // attack should generally not be possible anyway.
           $fetch_uri = $current;
           $fetch_host = null;
         }
 
         $future = id(new HTTPSFuture($fetch_uri))
           ->setFollowLocation(false)
           ->setTimeout($timeout);
 
         if ($fetch_host !== null) {
           $future->addHeader('Host', $fetch_host);
         }
 
         list($status, $body, $headers) = $future->resolve();
 
         if ($status->isRedirect()) {
           // This is an HTTP 3XX status, so look for a "Location" header.
           $location = null;
           foreach ($headers as $header) {
             list($name, $value) = $header;
             if (phutil_utf8_strtolower($name) == 'location') {
               $location = $value;
               break;
             }
           }
 
           // HTTP 3XX status with no "Location" header, just treat this like
           // a normal HTTP error.
           if ($location === null) {
             throw $status;
           }
 
           if (isset($redirects[$location])) {
             throw new Exception(
               pht('Encountered loop while following redirects.'));
           }
 
           $redirects[$location] = $location;
           $current = $location;
           // We'll fall off the bottom and go try this URI now.
         } else if ($status->isError()) {
           // This is something other than an HTTP 2XX or HTTP 3XX status, so
           // just bail out.
           throw $status;
         } else {
           // This is HTTP 2XX, so use the response body to save the
           // file data.
           $params = $params + array(
             'name' => basename($uri),
           );
 
           return self::newFromFileData($body, $params);
         }
       } catch (Exception $ex) {
         if ($redirects) {
           throw new PhutilProxyException(
             pht(
               'Failed to fetch remote URI "%s" after following %s redirect(s) '.
               '(%s): %s',
               $uri,
               phutil_count($redirects),
               implode(' > ', array_keys($redirects)),
               $ex->getMessage()),
             $ex);
         } else {
           throw $ex;
         }
       }
     }
   }
 
   public static function normalizeFileName($file_name) {
     $pattern = "@[\\x00-\\x19#%&+!~'\$\"\/=\\\\?<> ]+@";
     $file_name = preg_replace($pattern, '_', $file_name);
     $file_name = preg_replace('@_+@', '_', $file_name);
     $file_name = trim($file_name, '_');
 
     $disallowed_filenames = array(
       '.'  => 'dot',
       '..' => 'dotdot',
       ''   => 'file',
     );
     $file_name = idx($disallowed_filenames, $file_name, $file_name);
 
     return $file_name;
   }
 
   public function delete() {
     // We want to delete all the rows which mark this file as the transformation
     // of some other file (since we're getting rid of it). We also delete all
     // the transformations of this file, so that a user who deletes an image
     // doesn't need to separately hunt down and delete a bunch of thumbnails and
     // resizes of it.
 
     $outbound_xforms = id(new PhabricatorFileQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withTransforms(
         array(
           array(
             'originalPHID' => $this->getPHID(),
             'transform'    => true,
           ),
         ))
       ->execute();
 
     foreach ($outbound_xforms as $outbound_xform) {
       $outbound_xform->delete();
     }
 
     $inbound_xforms = id(new PhabricatorTransformedFile())->loadAllWhere(
       'transformedPHID = %s',
       $this->getPHID());
 
     $this->openTransaction();
       foreach ($inbound_xforms as $inbound_xform) {
         $inbound_xform->delete();
       }
       $ret = parent::delete();
     $this->saveTransaction();
 
     $this->deleteFileDataIfUnused(
       $this->instantiateStorageEngine(),
       $this->getStorageEngine(),
       $this->getStorageHandle());
 
     return $ret;
   }
 
 
   /**
    * Destroy stored file data if there are no remaining files which reference
    * it.
    */
   public function deleteFileDataIfUnused(
     PhabricatorFileStorageEngine $engine,
     $engine_identifier,
     $handle) {
 
     // Check to see if any files are using storage.
     $usage = id(new PhabricatorFile())->loadAllWhere(
       'storageEngine = %s AND storageHandle = %s LIMIT 1',
       $engine_identifier,
       $handle);
 
     // If there are no files using the storage, destroy the actual storage.
     if (!$usage) {
       try {
         $engine->deleteFile($handle);
       } catch (Exception $ex) {
         // In the worst case, we're leaving some data stranded in a storage
         // engine, which is not a big deal.
         phlog($ex);
       }
     }
   }
 
 
   public static function hashFileContent($data) {
     return sha1($data);
   }
 
   public function loadFileData() {
     $iterator = $this->getFileDataIterator();
     return $this->loadDataFromIterator($iterator);
   }
 
 
   /**
    * Return an iterable which emits file content bytes.
    *
    * @param int Offset for the start of data.
    * @param int Offset for the end of data.
    * @return Iterable Iterable object which emits requested data.
    */
   public function getFileDataIterator($begin = null, $end = null) {
     $engine = $this->instantiateStorageEngine();
     $raw_iterator = $engine->getRawFileDataIterator($this, $begin, $end);
 
     $key = $this->getStorageFormat();
 
     $format = id(clone PhabricatorFileStorageFormat::requireFormat($key))
       ->setFile($this);
 
     return $format->newReadIterator($raw_iterator);
   }
 
 
   public function getViewURI() {
     if (!$this->getPHID()) {
       throw new Exception(
         pht('You must save a file before you can generate a view URI.'));
     }
 
     return $this->getCDNURI();
   }
 
   public function getCDNURI() {
     $name = self::normalizeFileName($this->getName());
     $name = phutil_escape_uri($name);
 
     $parts = array();
     $parts[] = 'file';
     $parts[] = 'data';
 
     // If this is an instanced install, add the instance identifier to the URI.
     // Instanced configurations behind a CDN may not be able to control the
     // request domain used by the CDN (as with AWS CloudFront). Embedding the
     // instance identity in the path allows us to distinguish between requests
     // originating from different instances but served through the same CDN.
     $instance = PhabricatorEnv::getEnvConfig('cluster.instance');
     if (strlen($instance)) {
       $parts[] = '@'.$instance;
     }
 
     $parts[] = $this->getSecretKey();
     $parts[] = $this->getPHID();
     $parts[] = $name;
 
     $path = '/'.implode('/', $parts);
 
     // If this file is only partially uploaded, we're just going to return a
     // local URI to make sure that Ajax works, since the page is inevitably
     // going to give us an error back.
     if ($this->getIsPartial()) {
       return PhabricatorEnv::getURI($path);
     } else {
       return PhabricatorEnv::getCDNURI($path);
     }
   }
 
 
   public function getInfoURI() {
     return '/'.$this->getMonogram();
   }
 
   public function getBestURI() {
     if ($this->isViewableInBrowser()) {
       return $this->getViewURI();
     } else {
       return $this->getInfoURI();
     }
   }
 
   public function getDownloadURI() {
     $uri = id(new PhutilURI($this->getViewURI()))
       ->setQueryParam('download', true);
     return (string)$uri;
   }
 
   public function getURIForTransform(PhabricatorFileTransform $transform) {
     return $this->getTransformedURI($transform->getTransformKey());
   }
 
   private function getTransformedURI($transform) {
     $parts = array();
     $parts[] = 'file';
     $parts[] = 'xform';
 
     $instance = PhabricatorEnv::getEnvConfig('cluster.instance');
     if (strlen($instance)) {
       $parts[] = '@'.$instance;
     }
 
     $parts[] = $transform;
     $parts[] = $this->getPHID();
     $parts[] = $this->getSecretKey();
 
     $path = implode('/', $parts);
     $path = $path.'/';
 
     return PhabricatorEnv::getCDNURI($path);
   }
 
   public function isViewableInBrowser() {
     return ($this->getViewableMimeType() !== null);
   }
 
   public function isViewableImage() {
     if (!$this->isViewableInBrowser()) {
       return false;
     }
 
     $mime_map = PhabricatorEnv::getEnvConfig('files.image-mime-types');
     $mime_type = $this->getMimeType();
     return idx($mime_map, $mime_type);
   }
 
   public function isAudio() {
     if (!$this->isViewableInBrowser()) {
       return false;
     }
 
     $mime_map = PhabricatorEnv::getEnvConfig('files.audio-mime-types');
     $mime_type = $this->getMimeType();
     return idx($mime_map, $mime_type);
   }
 
   public function isVideo() {
     if (!$this->isViewableInBrowser()) {
       return false;
     }
 
     $mime_map = PhabricatorEnv::getEnvConfig('files.video-mime-types');
     $mime_type = $this->getMimeType();
     return idx($mime_map, $mime_type);
   }
 
   public function isTransformableImage() {
     // NOTE: The way the 'gd' extension works in PHP is that you can install it
     // with support for only some file types, so it might be able to handle
     // PNG but not JPEG. Try to generate thumbnails for whatever we can. Setup
     // warns you if you don't have complete support.
 
     $matches = null;
     $ok = preg_match(
       '@^image/(gif|png|jpe?g)@',
       $this->getViewableMimeType(),
       $matches);
     if (!$ok) {
       return false;
     }
 
     switch ($matches[1]) {
       case 'jpg';
       case 'jpeg':
         return function_exists('imagejpeg');
         break;
       case 'png':
         return function_exists('imagepng');
         break;
       case 'gif':
         return function_exists('imagegif');
         break;
       default:
         throw new Exception(pht('Unknown type matched as image MIME type.'));
     }
   }
 
   public static function getTransformableImageFormats() {
     $supported = array();
 
     if (function_exists('imagejpeg')) {
       $supported[] = 'jpg';
     }
 
     if (function_exists('imagepng')) {
       $supported[] = 'png';
     }
 
     if (function_exists('imagegif')) {
       $supported[] = 'gif';
     }
 
     return $supported;
   }
 
   public function getDragAndDropDictionary() {
     return array(
       'id'   => $this->getID(),
       'phid' => $this->getPHID(),
       'uri'  => $this->getBestURI(),
     );
   }
 
   public function instantiateStorageEngine() {
     return self::buildEngine($this->getStorageEngine());
   }
 
   public static function buildEngine($engine_identifier) {
     $engines = self::buildAllEngines();
     foreach ($engines as $engine) {
       if ($engine->getEngineIdentifier() == $engine_identifier) {
         return $engine;
       }
     }
 
     throw new Exception(
       pht(
         "Storage engine '%s' could not be located!",
         $engine_identifier));
   }
 
   public static function buildAllEngines() {
     return id(new PhutilClassMapQuery())
       ->setAncestorClass('PhabricatorFileStorageEngine')
       ->execute();
   }
 
   public function getViewableMimeType() {
     $mime_map = PhabricatorEnv::getEnvConfig('files.viewable-mime-types');
 
     $mime_type = $this->getMimeType();
     $mime_parts = explode(';', $mime_type);
     $mime_type = trim(reset($mime_parts));
 
     return idx($mime_map, $mime_type);
   }
 
   public function getDisplayIconForMimeType() {
     $mime_map = PhabricatorEnv::getEnvConfig('files.icon-mime-types');
     $mime_type = $this->getMimeType();
     return idx($mime_map, $mime_type, 'fa-file-o');
   }
 
   public function validateSecretKey($key) {
     return ($key == $this->getSecretKey());
   }
 
   public function generateSecretKey() {
     return Filesystem::readRandomCharacters(20);
   }
 
   public function setStorageProperties(array $properties) {
     $this->metadata[self::METADATA_STORAGE] = $properties;
     return $this;
   }
 
   public function getStorageProperties() {
     return idx($this->metadata, self::METADATA_STORAGE, array());
   }
 
   public function getStorageProperty($key, $default = null) {
     $properties = $this->getStorageProperties();
     return idx($properties, $key, $default);
   }
 
   public function loadDataFromIterator($iterator) {
     $result = '';
 
     foreach ($iterator as $chunk) {
       $result .= $chunk;
     }
 
     return $result;
   }
 
   public function updateDimensions($save = true) {
     if (!$this->isViewableImage()) {
       throw new Exception(pht('This file is not a viewable image.'));
     }
 
     if (!function_exists('imagecreatefromstring')) {
       throw new Exception(pht('Cannot retrieve image information.'));
     }
 
     $data = $this->loadFileData();
 
     $img = imagecreatefromstring($data);
     if ($img === false) {
       throw new Exception(pht('Error when decoding image.'));
     }
 
     $this->metadata[self::METADATA_IMAGE_WIDTH] = imagesx($img);
     $this->metadata[self::METADATA_IMAGE_HEIGHT] = imagesy($img);
 
     if ($save) {
       $this->save();
     }
 
     return $this;
   }
 
   public function copyDimensions(PhabricatorFile $file) {
     $metadata = $file->getMetadata();
     $width = idx($metadata, self::METADATA_IMAGE_WIDTH);
     if ($width) {
       $this->metadata[self::METADATA_IMAGE_WIDTH] = $width;
     }
     $height = idx($metadata, self::METADATA_IMAGE_HEIGHT);
     if ($height) {
       $this->metadata[self::METADATA_IMAGE_HEIGHT] = $height;
     }
 
     return $this;
   }
 
 
   /**
    * Load (or build) the {@class:PhabricatorFile} objects for builtin file
    * resources. The builtin mechanism allows files shipped with Phabricator
    * to be treated like normal files so that APIs do not need to special case
    * things like default images or deleted files.
    *
    * Builtins are located in `resources/builtin/` and identified by their
    * name.
    *
    * @param  PhabricatorUser Viewing user.
    * @param  list<PhabricatorFilesBuiltinFile> List of builtin file specs.
    * @return dict<string, PhabricatorFile> Dictionary of named builtins.
    */
   public static function loadBuiltins(PhabricatorUser $user, array $builtins) {
     $builtins = mpull($builtins, null, 'getBuiltinFileKey');
 
-    $specs = array();
-    foreach ($builtins as $key => $buitin) {
-      $specs[] = array(
-        'originalPHID' => PhabricatorPHIDConstants::PHID_VOID,
-        'transform'    => $key,
-      );
-    }
-
     // NOTE: Anyone is allowed to access builtin files.
 
     $files = id(new PhabricatorFileQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
-      ->withTransforms($specs)
+      ->withBuiltinKeys(array_keys($builtins))
       ->execute();
 
     $results = array();
     foreach ($files as $file) {
       $builtin_key = $file->getBuiltinName();
       if ($builtin_key !== null) {
         $results[$builtin_key] = $file;
       }
     }
 
     $build = array();
     foreach ($builtins as $key => $builtin) {
       if (isset($results[$key])) {
         continue;
       }
 
       $data = $builtin->loadBuiltinFileData();
 
       $params = array(
         'name' => $builtin->getBuiltinDisplayName(),
         'ttl'  => time() + (60 * 60 * 24 * 7),
         'canCDN' => true,
         'builtin' => $key,
       );
 
       $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
-        $file = self::newFromFileData($data, $params);
-        $xform = id(new PhabricatorTransformedFile())
-          ->setOriginalPHID(PhabricatorPHIDConstants::PHID_VOID)
-          ->setTransform($key)
-          ->setTransformedPHID($file->getPHID())
-          ->save();
+        try {
+          $file = self::newFromFileData($data, $params);
+        } catch (AphrontDuplicateKeyQueryException $ex) {
+          $file = id(new PhabricatorFileQuery())
+            ->setViewer(PhabricatorUser::getOmnipotentUser())
+            ->withBuiltinKeys(array($key))
+            ->executeOne();
+          if (!$file) {
+            throw new Exception(
+              pht(
+                'Collided mid-air when generating builtin file "%s", but '.
+                'then failed to load the object we collided with.',
+                $key));
+          }
+        }
       unset($unguarded);
 
       $file->attachObjectPHIDs(array());
       $file->attachObjects(array());
 
       $results[$key] = $file;
     }
 
     return $results;
   }
 
 
   /**
    * Convenience wrapper for @{method:loadBuiltins}.
    *
    * @param PhabricatorUser   Viewing user.
    * @param string            Single builtin name to load.
    * @return PhabricatorFile  Corresponding builtin file.
    */
   public static function loadBuiltin(PhabricatorUser $user, $name) {
     $builtin = id(new PhabricatorFilesOnDiskBuiltinFile())
       ->setName($name);
 
     $key = $builtin->getBuiltinFileKey();
 
     return idx(self::loadBuiltins($user, array($builtin)), $key);
   }
 
   public function getObjects() {
     return $this->assertAttached($this->objects);
   }
 
   public function attachObjects(array $objects) {
     $this->objects = $objects;
     return $this;
   }
 
   public function getObjectPHIDs() {
     return $this->assertAttached($this->objectPHIDs);
   }
 
   public function attachObjectPHIDs(array $object_phids) {
     $this->objectPHIDs = $object_phids;
     return $this;
   }
 
   public function getOriginalFile() {
     return $this->assertAttached($this->originalFile);
   }
 
   public function attachOriginalFile(PhabricatorFile $file = null) {
     $this->originalFile = $file;
     return $this;
   }
 
   public function getImageHeight() {
     if (!$this->isViewableImage()) {
       return null;
     }
     return idx($this->metadata, self::METADATA_IMAGE_HEIGHT);
   }
 
   public function getImageWidth() {
     if (!$this->isViewableImage()) {
       return null;
     }
     return idx($this->metadata, self::METADATA_IMAGE_WIDTH);
   }
 
   public function getCanCDN() {
     if (!$this->isViewableImage()) {
       return false;
     }
 
     return idx($this->metadata, self::METADATA_CAN_CDN);
   }
 
   public function setCanCDN($can_cdn) {
     $this->metadata[self::METADATA_CAN_CDN] = $can_cdn ? 1 : 0;
     return $this;
   }
 
   public function isBuiltin() {
     return ($this->getBuiltinName() !== null);
   }
 
   public function getBuiltinName() {
     return idx($this->metadata, self::METADATA_BUILTIN);
   }
 
   public function setBuiltinName($name) {
     $this->metadata[self::METADATA_BUILTIN] = $name;
     return $this;
   }
 
   public function getIsProfileImage() {
     return idx($this->metadata, self::METADATA_PROFILE);
   }
 
   public function setIsProfileImage($value) {
     $this->metadata[self::METADATA_PROFILE] = $value;
     return $this;
   }
 
   /**
    * Write the policy edge between this file and some object.
    *
    * @param phid Object PHID to attach to.
    * @return this
    */
   public function attachToObject($phid) {
     $edge_type = PhabricatorObjectHasFileEdgeType::EDGECONST;
 
     id(new PhabricatorEdgeEditor())
       ->addEdge($phid, $edge_type, $this->getPHID())
       ->save();
 
     return $this;
   }
 
 
   /**
    * Remove the policy edge between this file and some object.
    *
    * @param phid Object PHID to detach from.
    * @return this
    */
   public function detachFromObject($phid) {
     $edge_type = PhabricatorObjectHasFileEdgeType::EDGECONST;
 
     id(new PhabricatorEdgeEditor())
       ->removeEdge($phid, $edge_type, $this->getPHID())
       ->save();
 
     return $this;
   }
 
 
   /**
    * Configure a newly created file object according to specified parameters.
    *
    * This method is called both when creating a file from fresh data, and
    * when creating a new file which reuses existing storage.
    *
    * @param map<string, wild>   Bag of parameters, see @{class:PhabricatorFile}
    *  for documentation.
    * @return this
    */
   private function readPropertiesFromParameters(array $params) {
     $file_name = idx($params, 'name');
     $this->setName($file_name);
 
     $author_phid = idx($params, 'authorPHID');
     $this->setAuthorPHID($author_phid);
 
     $file_ttl = idx($params, 'ttl');
     $this->setTtl($file_ttl);
 
     $view_policy = idx($params, 'viewPolicy');
     if ($view_policy) {
       $this->setViewPolicy($params['viewPolicy']);
     }
 
     $is_explicit = (idx($params, 'isExplicitUpload') ? 1 : 0);
     $this->setIsExplicitUpload($is_explicit);
 
     $can_cdn = idx($params, 'canCDN');
     if ($can_cdn) {
       $this->setCanCDN(true);
     }
 
     $builtin = idx($params, 'builtin');
     if ($builtin) {
       $this->setBuiltinName($builtin);
+      $this->setBuiltinKey($builtin);
     }
 
     $profile = idx($params, 'profile');
     if ($profile) {
       $this->setIsProfileImage(true);
     }
 
     $mime_type = idx($params, 'mime-type');
     if ($mime_type) {
       $this->setMimeType($mime_type);
     }
 
     return $this;
   }
 
   public function getRedirectResponse() {
     $uri = $this->getBestURI();
 
     // TODO: This is a bit iffy. Sometimes, getBestURI() returns a CDN URI
     // (if the file is a viewable image) and sometimes a local URI (if not).
     // For now, just detect which one we got and configure the response
     // appropriately. In the long run, if this endpoint is served from a CDN
     // domain, we can't issue a local redirect to an info URI (which is not
     // present on the CDN domain). We probably never actually issue local
     // redirects here anyway, since we only ever transform viewable images
     // right now.
 
     $is_external = strlen(id(new PhutilURI($uri))->getDomain());
 
     return id(new AphrontRedirectResponse())
       ->setIsExternal($is_external)
       ->setURI($uri);
   }
 
   public function attachTransforms(array $map) {
     $this->transforms = $map;
     return $this;
   }
 
   public function getTransform($key) {
     return $this->assertAttachedKey($this->transforms, $key);
   }
 
 
 /* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
 
 
   public function getApplicationTransactionEditor() {
     return new PhabricatorFileEditor();
   }
 
   public function getApplicationTransactionObject() {
     return $this;
   }
 
   public function getApplicationTransactionTemplate() {
     return new PhabricatorFileTransaction();
   }
 
   public function willRenderTimeline(
     PhabricatorApplicationTransactionView $timeline,
     AphrontRequest $request) {
 
     return $timeline;
   }
 
 
 /* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
       PhabricatorPolicyCapability::CAN_EDIT,
     );
   }
 
   public function getPolicy($capability) {
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         if ($this->isBuiltin()) {
           return PhabricatorPolicies::getMostOpenPolicy();
         }
         if ($this->getIsProfileImage()) {
           return PhabricatorPolicies::getMostOpenPolicy();
         }
         return $this->getViewPolicy();
       case PhabricatorPolicyCapability::CAN_EDIT:
         return PhabricatorPolicies::POLICY_NOONE;
     }
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     $viewer_phid = $viewer->getPHID();
     if ($viewer_phid) {
       if ($this->getAuthorPHID() == $viewer_phid) {
         return true;
       }
     }
 
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         // If you can see the file this file is a transform of, you can see
         // this file.
         if ($this->getOriginalFile()) {
           return true;
         }
 
         // If you can see any object this file is attached to, you can see
         // the file.
         return (count($this->getObjects()) > 0);
     }
 
     return false;
   }
 
   public function describeAutomaticCapability($capability) {
     $out = array();
     $out[] = pht('The user who uploaded a file can always view and edit it.');
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         $out[] = pht(
           'Files attached to objects are visible to users who can view '.
           'those objects.');
         $out[] = pht(
           'Thumbnails are visible only to users who can view the original '.
           'file.');
         break;
     }
 
     return $out;
   }
 
 
 /* -(  PhabricatorSubscribableInterface Implementation  )-------------------- */
 
 
   public function isAutomaticallySubscribed($phid) {
     return ($this->authorPHID == $phid);
   }
 
 
 /* -(  PhabricatorTokenReceiverInterface  )---------------------------------- */
 
 
   public function getUsersToNotifyOfTokenGiven() {
     return array(
       $this->getAuthorPHID(),
     );
   }
 
 
 /* -(  PhabricatorDestructibleInterface  )----------------------------------- */
 
 
   public function destroyObjectPermanently(
     PhabricatorDestructionEngine $engine) {
 
     $this->openTransaction();
       $this->delete();
     $this->saveTransaction();
   }
 
 }