diff --git a/src/applications/differential/render/DifferentialChangesetRenderer.php b/src/applications/differential/render/DifferentialChangesetRenderer.php
index 26de5cb53b..4ed77bf041 100644
--- a/src/applications/differential/render/DifferentialChangesetRenderer.php
+++ b/src/applications/differential/render/DifferentialChangesetRenderer.php
@@ -1,718 +1,723 @@
 <?php
 
 abstract class DifferentialChangesetRenderer extends Phobject {
 
   private $user;
   private $changeset;
   private $renderingReference;
   private $renderPropertyChangeHeader;
   private $isTopLevel;
   private $isUndershield;
   private $hunkStartLines;
   private $oldLines;
   private $newLines;
   private $oldComments;
   private $newComments;
   private $oldChangesetID;
   private $newChangesetID;
   private $oldAttachesToNewFile;
   private $newAttachesToNewFile;
   private $highlightOld = array();
   private $highlightNew = array();
   private $codeCoverage;
   private $handles;
   private $markupEngine;
   private $oldRender;
   private $newRender;
   private $originalOld;
   private $originalNew;
   private $gaps;
   private $mask;
   private $originalCharacterEncoding;
   private $showEditAndReplyLinks;
   private $canMarkDone;
   private $objectOwnerPHID;
   private $highlightingDisabled;
   private $scopeEngine = false;
   private $depthOnlyLines;
 
   private $oldFile = false;
   private $newFile = false;
 
   abstract public function getRendererKey();
 
   public function setShowEditAndReplyLinks($bool) {
     $this->showEditAndReplyLinks = $bool;
     return $this;
   }
 
   public function getShowEditAndReplyLinks() {
     return $this->showEditAndReplyLinks;
   }
 
   public function setHighlightingDisabled($highlighting_disabled) {
     $this->highlightingDisabled = $highlighting_disabled;
     return $this;
   }
 
   public function getHighlightingDisabled() {
     return $this->highlightingDisabled;
   }
 
   public function setOriginalCharacterEncoding($original_character_encoding) {
     $this->originalCharacterEncoding = $original_character_encoding;
     return $this;
   }
 
   public function getOriginalCharacterEncoding() {
     return $this->originalCharacterEncoding;
   }
 
   public function setIsUndershield($is_undershield) {
     $this->isUndershield = $is_undershield;
     return $this;
   }
 
   public function getIsUndershield() {
     return $this->isUndershield;
   }
 
   public function setMask($mask) {
     $this->mask = $mask;
     return $this;
   }
   protected function getMask() {
     return $this->mask;
   }
 
   public function setGaps($gaps) {
     $this->gaps = $gaps;
     return $this;
   }
   protected function getGaps() {
     return $this->gaps;
   }
 
   public function setDepthOnlyLines(array $lines) {
     $this->depthOnlyLines = $lines;
     return $this;
   }
 
   public function getDepthOnlyLines() {
     return $this->depthOnlyLines;
   }
 
   public function attachOldFile(PhabricatorFile $old = null) {
     $this->oldFile = $old;
     return $this;
   }
 
   public function getOldFile() {
     if ($this->oldFile === false) {
       throw new PhabricatorDataNotAttachedException($this);
     }
     return $this->oldFile;
   }
 
   public function hasOldFile() {
     return (bool)$this->oldFile;
   }
 
   public function attachNewFile(PhabricatorFile $new = null) {
     $this->newFile = $new;
     return $this;
   }
 
   public function getNewFile() {
     if ($this->newFile === false) {
       throw new PhabricatorDataNotAttachedException($this);
     }
     return $this->newFile;
   }
 
   public function hasNewFile() {
     return (bool)$this->newFile;
   }
 
   public function setOriginalNew($original_new) {
     $this->originalNew = $original_new;
     return $this;
   }
   protected function getOriginalNew() {
     return $this->originalNew;
   }
 
   public function setOriginalOld($original_old) {
     $this->originalOld = $original_old;
     return $this;
   }
   protected function getOriginalOld() {
     return $this->originalOld;
   }
 
   public function setNewRender($new_render) {
     $this->newRender = $new_render;
     return $this;
   }
   protected function getNewRender() {
     return $this->newRender;
   }
 
   public function setOldRender($old_render) {
     $this->oldRender = $old_render;
     return $this;
   }
   protected function getOldRender() {
     return $this->oldRender;
   }
 
   public function setMarkupEngine(PhabricatorMarkupEngine $markup_engine) {
     $this->markupEngine = $markup_engine;
     return $this;
   }
   public function getMarkupEngine() {
     return $this->markupEngine;
   }
 
   public function setHandles(array $handles) {
     assert_instances_of($handles, 'PhabricatorObjectHandle');
     $this->handles = $handles;
     return $this;
   }
   protected function getHandles() {
     return $this->handles;
   }
 
   public function setCodeCoverage($code_coverage) {
     $this->codeCoverage = $code_coverage;
     return $this;
   }
   protected function getCodeCoverage() {
     return $this->codeCoverage;
   }
 
   public function setHighlightNew($highlight_new) {
     $this->highlightNew = $highlight_new;
     return $this;
   }
   protected function getHighlightNew() {
     return $this->highlightNew;
   }
 
   public function setHighlightOld($highlight_old) {
     $this->highlightOld = $highlight_old;
     return $this;
   }
   protected function getHighlightOld() {
     return $this->highlightOld;
   }
 
   public function setNewAttachesToNewFile($attaches) {
     $this->newAttachesToNewFile = $attaches;
     return $this;
   }
   protected function getNewAttachesToNewFile() {
     return $this->newAttachesToNewFile;
   }
 
   public function setOldAttachesToNewFile($attaches) {
     $this->oldAttachesToNewFile = $attaches;
     return $this;
   }
   protected function getOldAttachesToNewFile() {
     return $this->oldAttachesToNewFile;
   }
 
   public function setNewChangesetID($new_changeset_id) {
     $this->newChangesetID = $new_changeset_id;
     return $this;
   }
   protected function getNewChangesetID() {
     return $this->newChangesetID;
   }
 
   public function setOldChangesetID($old_changeset_id) {
     $this->oldChangesetID = $old_changeset_id;
     return $this;
   }
   protected function getOldChangesetID() {
     return $this->oldChangesetID;
   }
 
   public function setNewComments(array $new_comments) {
     foreach ($new_comments as $line_number => $comments) {
       assert_instances_of($comments, 'PhabricatorInlineCommentInterface');
     }
     $this->newComments = $new_comments;
     return $this;
   }
   protected function getNewComments() {
     return $this->newComments;
   }
 
   public function setOldComments(array $old_comments) {
     foreach ($old_comments as $line_number => $comments) {
       assert_instances_of($comments, 'PhabricatorInlineCommentInterface');
     }
     $this->oldComments = $old_comments;
     return $this;
   }
   protected function getOldComments() {
     return $this->oldComments;
   }
 
   public function setNewLines(array $new_lines) {
     $this->newLines = $new_lines;
     return $this;
   }
   protected function getNewLines() {
     return $this->newLines;
   }
 
   public function setOldLines(array $old_lines) {
     $this->oldLines = $old_lines;
     return $this;
   }
   protected function getOldLines() {
     return $this->oldLines;
   }
 
   public function setHunkStartLines(array $hunk_start_lines) {
     $this->hunkStartLines = $hunk_start_lines;
     return $this;
   }
 
   protected function getHunkStartLines() {
     return $this->hunkStartLines;
   }
 
   public function setUser(PhabricatorUser $user) {
     $this->user = $user;
     return $this;
   }
   protected function getUser() {
     return $this->user;
   }
 
   public function setChangeset(DifferentialChangeset $changeset) {
     $this->changeset = $changeset;
     return $this;
   }
   protected function getChangeset() {
     return $this->changeset;
   }
 
   public function setRenderingReference($rendering_reference) {
     $this->renderingReference = $rendering_reference;
     return $this;
   }
   protected function getRenderingReference() {
     return $this->renderingReference;
   }
 
   public function setRenderPropertyChangeHeader($should_render) {
     $this->renderPropertyChangeHeader = $should_render;
     return $this;
   }
 
   private function shouldRenderPropertyChangeHeader() {
     return $this->renderPropertyChangeHeader;
   }
 
   public function setIsTopLevel($is) {
     $this->isTopLevel = $is;
     return $this;
   }
 
   private function getIsTopLevel() {
     return $this->isTopLevel;
   }
 
   public function setCanMarkDone($can_mark_done) {
     $this->canMarkDone = $can_mark_done;
     return $this;
   }
 
   public function getCanMarkDone() {
     return $this->canMarkDone;
   }
 
   public function setObjectOwnerPHID($phid) {
     $this->objectOwnerPHID = $phid;
     return $this;
   }
 
   public function getObjectOwnerPHID() {
     return $this->objectOwnerPHID;
   }
 
   final public function renderChangesetTable($content) {
     $props = null;
     if ($this->shouldRenderPropertyChangeHeader()) {
       $props = $this->renderPropertyChangeHeader();
     }
 
     $notice = null;
     if ($this->getIsTopLevel()) {
       $force = (!$content && !$props);
       $notice = $this->renderChangeTypeHeader($force);
     }
 
     $undershield = null;
     if ($this->getIsUndershield()) {
       $undershield = $this->renderUndershieldHeader();
     }
 
     $result = array(
       $notice,
       $props,
       $undershield,
       $content,
     );
 
     return hsprintf('%s', $result);
   }
 
   abstract public function isOneUpRenderer();
   abstract public function renderTextChange(
     $range_start,
     $range_len,
     $rows);
   abstract public function renderFileChange(
     $old = null,
     $new = null,
     $id = 0,
     $vs = 0);
 
   abstract protected function renderChangeTypeHeader($force);
   abstract protected function renderUndershieldHeader();
 
   protected function didRenderChangesetTableContents($contents) {
     return $contents;
   }
 
   /**
    * Render a "shield" over the diff, with a message like "This file is
    * generated and does not need to be reviewed." or "This file was completely
    * deleted." This UI element hides unimportant text so the reviewer doesn't
    * need to scroll past it.
    *
    * The shield includes a link to view the underlying content. This link
    * may force certain rendering modes when the link is clicked:
    *
    *    - `"default"`: Render the diff normally, as though it was not
    *      shielded. This is the default and appropriate if the underlying
    *      diff is a normal change, but was hidden for reasons of not being
    *      important (e.g., generated code).
    *    - `"text"`: Force the text to be shown. This is probably only relevant
    *      when a file is not changed.
    *    - `"none"`: Don't show the link (e.g., text not available).
    *
    * @param   string        Message explaining why the diff is hidden.
    * @param   string|null   Force mode, see above.
    * @return  string        Shield markup.
    */
   abstract public function renderShield($message, $force = 'default');
 
   abstract protected function renderPropertyChangeHeader();
 
   protected function buildPrimitives($range_start, $range_len) {
     $primitives = array();
 
     $hunk_starts = $this->getHunkStartLines();
 
     $mask = $this->getMask();
     $gaps = $this->getGaps();
 
     $old = $this->getOldLines();
     $new = $this->getNewLines();
     $old_render = $this->getOldRender();
     $new_render = $this->getNewRender();
     $old_comments = $this->getOldComments();
     $new_comments = $this->getNewComments();
 
     $size = count($old);
     for ($ii = $range_start; $ii < $range_start + $range_len; $ii++) {
       if (empty($mask[$ii])) {
         list($top, $len) = array_pop($gaps);
         $primitives[] = array(
           'type' => 'context',
           'top' => $top,
           'len' => $len,
         );
 
         $ii += ($len - 1);
         continue;
       }
 
       $ospec = array(
         'type' => 'old',
         'htype' => null,
         'cursor' => $ii,
         'line' => null,
         'oline' => null,
         'render' => null,
       );
 
       $nspec = array(
         'type' => 'new',
         'htype' => null,
         'cursor' => $ii,
         'line' => null,
         'oline' => null,
         'render' => null,
         'copy' => null,
         'coverage' => null,
       );
 
       if (isset($old[$ii])) {
         $ospec['line'] = (int)$old[$ii]['line'];
         $nspec['oline'] = (int)$old[$ii]['line'];
         $ospec['htype'] = $old[$ii]['type'];
         if (isset($old_render[$ii])) {
           $ospec['render'] = $old_render[$ii];
         }
       }
 
       if (isset($new[$ii])) {
         $nspec['line'] = (int)$new[$ii]['line'];
         $ospec['oline'] = (int)$new[$ii]['line'];
         $nspec['htype'] = $new[$ii]['type'];
         if (isset($new_render[$ii])) {
           $nspec['render'] = $new_render[$ii];
         }
       }
 
       if (isset($hunk_starts[$ospec['line']])) {
         $primitives[] = array(
           'type' => 'no-context',
         );
       }
 
       $primitives[] = $ospec;
       $primitives[] = $nspec;
 
       if ($ospec['line'] !== null && isset($old_comments[$ospec['line']])) {
         foreach ($old_comments[$ospec['line']] as $comment) {
           $primitives[] = array(
             'type' => 'inline',
             'comment' => $comment,
             'right' => false,
           );
         }
       }
 
       if ($nspec['line'] !== null && isset($new_comments[$nspec['line']])) {
         foreach ($new_comments[$nspec['line']] as $comment) {
           $primitives[] = array(
             'type' => 'inline',
             'comment' => $comment,
             'right' => true,
           );
         }
       }
 
       if ($hunk_starts && ($ii == $size - 1)) {
         $primitives[] = array(
           'type' => 'no-context',
         );
       }
     }
 
     if ($this->isOneUpRenderer()) {
       $primitives = $this->processPrimitivesForOneUp($primitives);
     }
 
     return $primitives;
   }
 
   private function processPrimitivesForOneUp(array $primitives) {
     // Primitives come out of buildPrimitives() in two-up format, because it
     // is the most general, flexible format. To put them into one-up format,
     // we need to filter and reorder them. In particular:
     //
     //   - We discard unchanged lines in the old file; in one-up format, we
     //     render them only once.
     //   - We group contiguous blocks of old-modified and new-modified lines, so
     //     they render in "block of old, block of new" order instead of
     //     alternating old and new lines.
 
     $out = array();
 
     $old_buf = array();
     $new_buf = array();
     foreach ($primitives as $primitive) {
       $type = $primitive['type'];
 
       if ($type == 'old') {
         if (!$primitive['htype']) {
           // This is a line which appears in both the old file and the new
           // file, or the spacer corresponding to a line added in the new file.
           // Ignore it when rendering a one-up diff.
           continue;
         }
         $old_buf[] = $primitive;
       } else if ($type == 'new') {
         if ($primitive['line'] === null) {
           // This is an empty spacer corresponding to a line removed from the
           // old file. Ignore it when rendering a one-up diff.
           continue;
         }
         if (!$primitive['htype']) {
           // If this line is the same in both versions of the file, put it in
           // the old line buffer. This makes sure inlines on old, unchanged
           // lines end up in the right place.
 
           // First, we need to flush the line buffers if they're not empty.
           if ($old_buf) {
             $out[] = $old_buf;
             $old_buf = array();
           }
           if ($new_buf) {
             $out[] = $new_buf;
             $new_buf = array();
           }
           $old_buf[] = $primitive;
         } else {
           $new_buf[] = $primitive;
         }
       } else if ($type == 'context' || $type == 'no-context') {
         $out[] = $old_buf;
         $out[] = $new_buf;
         $old_buf = array();
         $new_buf = array();
         $out[] = array($primitive);
       } else if ($type == 'inline') {
 
         // If this inline is on the left side, put it after the old lines.
         if (!$primitive['right']) {
           $out[] = $old_buf;
           $out[] = array($primitive);
           $old_buf = array();
         } else {
           $out[] = $old_buf;
           $out[] = $new_buf;
           $out[] = array($primitive);
           $old_buf = array();
           $new_buf = array();
         }
 
       } else {
         throw new Exception(pht("Unknown primitive type '%s'!", $primitive));
       }
     }
 
     $out[] = $old_buf;
     $out[] = $new_buf;
     $out = array_mergev($out);
 
     return $out;
   }
 
   protected function getChangesetProperties($changeset) {
     $old = $changeset->getOldProperties();
     $new = $changeset->getNewProperties();
 
     // When adding files, don't show the uninteresting 644 filemode change.
     if ($changeset->getChangeType() == DifferentialChangeType::TYPE_ADD &&
         $new == array('unix:filemode' => '100644')) {
       unset($new['unix:filemode']);
     }
 
     // Likewise when removing files.
     if ($changeset->getChangeType() == DifferentialChangeType::TYPE_DELETE &&
         $old == array('unix:filemode' => '100644')) {
       unset($old['unix:filemode']);
     }
 
     $metadata = $changeset->getMetadata();
 
     if ($this->hasOldFile()) {
       $file = $this->getOldFile();
       if ($file->getImageWidth()) {
         $dimensions = $file->getImageWidth().'x'.$file->getImageHeight();
         $old['file:dimensions'] = $dimensions;
       }
       $old['file:mimetype'] = $file->getMimeType();
       $old['file:size'] = phutil_format_bytes($file->getByteSize());
     } else {
       $old['file:mimetype'] = idx($metadata, 'old:file:mime-type');
       $size = idx($metadata, 'old:file:size');
       if ($size !== null) {
         $old['file:size'] = phutil_format_bytes($size);
       }
     }
 
     if ($this->hasNewFile()) {
       $file = $this->getNewFile();
       if ($file->getImageWidth()) {
         $dimensions = $file->getImageWidth().'x'.$file->getImageHeight();
         $new['file:dimensions'] = $dimensions;
       }
       $new['file:mimetype'] = $file->getMimeType();
       $new['file:size'] = phutil_format_bytes($file->getByteSize());
     } else {
       $new['file:mimetype'] = idx($metadata, 'new:file:mime-type');
       $size = idx($metadata, 'new:file:size');
       if ($size !== null) {
         $new['file:size'] = phutil_format_bytes($size);
       }
     }
 
     return array($old, $new);
   }
 
   public function renderUndoTemplates() {
     $views = array(
       'l' => id(new PHUIDiffInlineCommentUndoView())->setIsOnRight(false),
       'r' => id(new PHUIDiffInlineCommentUndoView())->setIsOnRight(true),
     );
 
     foreach ($views as $key => $view) {
       $scaffold = $this->getRowScaffoldForInline($view);
       $views[$key] = id(new PHUIDiffInlineCommentTableScaffold())
         ->addRowScaffold($scaffold);
     }
 
     return $views;
   }
 
   final protected function getScopeEngine() {
     if ($this->scopeEngine === false) {
       $hunk_starts = $this->getHunkStartLines();
 
       // If this change is missing context, don't try to identify scopes, since
       // we won't really be able to get anywhere.
       $has_multiple_hunks = (count($hunk_starts) > 1);
-      $has_offset_hunks = (head_key($hunk_starts) != 1);
+
+      $has_offset_hunks = false;
+      if ($hunk_starts) {
+        $has_offset_hunks = (head_key($hunk_starts) != 1);
+      }
+
       $missing_context = ($has_multiple_hunks || $has_offset_hunks);
 
       if ($missing_context) {
         $scope_engine = null;
       } else {
         $line_map = $this->getNewLineTextMap();
         $scope_engine = id(new PhabricatorDiffScopeEngine())
           ->setLineTextMap($line_map);
       }
 
       $this->scopeEngine = $scope_engine;
     }
 
     return $this->scopeEngine;
   }
 
   private function getNewLineTextMap() {
     $new = $this->getNewLines();
 
     $text_map = array();
     foreach ($new as $new_line) {
       if (!isset($new_line['line'])) {
         continue;
       }
       $text_map[$new_line['line']] = $new_line['text'];
     }
 
     return $text_map;
   }
 
 }