Always parse the first line of a commit message as a title

Summary: Fixes T10312. If your first line is "Reviewers: xyz", it's a title, not a "Reviewers" field.

Test Plan: Added unit test.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10312

Differential Revision: https://secure.phabricator.com/D17122

src/applications/differential/parser/DifferentialCommitMessageParser.php

@@ -161,6 +161,14 @@ final class DifferentialCommitMessageParser extends Phobject {
 
     $field_map = array();
     foreach ($lines as $key => $line) {
+      // We always parse the first line of the message as a title, even if it
+      // contains something we recognize as a field header.
+      if (!isset($seen[$key_title])) {
+        $field = $key_title;
+
+        $lines[$key] = trim($line);
+        $seen[$field] = true;
+      } else {
         $match = null;
         if (preg_match($label_regexp, $line, $match)) {
           $lines[$key] = trim($match['text']);
@@ -168,10 +176,12 @@ final class DifferentialCommitMessageParser extends Phobject {
           if (!empty($seen[$field])) {
             $this->errors[] = pht(
               'Field "%s" occurs twice in commit message!',
-            $field);
+              $match['field']);
           }
           $seen[$field] = true;
         }
+      }
+
       $field_map[$key] = $field;
     }
 

src/applications/differential/parser/__tests__/messages/title-with-label.txt

@@ -0,0 +1,11 @@
+color: orange
+~~~~~~~~~~
+{
+  "color": "color"
+}
+~~~~~~~~~~
+{
+  "title": "color: orange"
+}
+~~~~~~~~~~
+[]