Unparse/escape macros with commas, etc., correctly

Summary: Fixes T2574.

Test Plan: {F33501}

Reviewers: vrana

Reviewed By: vrana

CC: aran

Maniphest Tasks: T2574

Differential Revision: https://secure.phabricator.com/D5062

src/applications/macro/controller/PhabricatorMacroMemeDialogController.php

@@ -28,8 +28,16 @@ final class PhabricatorMacroMemeDialogController
       }
 
       if (!$errors) {
+        $options = new PhutilSimpleOptions();
+        $data = array(
+          'src' => $name,
+          'above' => $above,
+          'below' => $below,
+        );
+        $string = $options->unparse($data, $escape = '}');
+
         $result = array(
-          'text' => "{meme, src={$name}, above={$above}, below={$below}}",
+          'text' => "{meme, {$string}}",
         );
         return id(new AphrontAjaxResponse())->setContent($result);
       }

src/infrastructure/markup/rule/PhabricatorRemarkupRuleMeme.php

@@ -10,7 +10,7 @@ final class PhabricatorRemarkupRuleMeme
 
   public function apply($text) {
     return preg_replace_callback(
-      '@{meme,([^}]+)}$@m',
+      '@{meme,((?:[^}\\\\]+|\\\\.)+)}$@m',
       array($this, 'markupMeme'),
       $text);
   }