Tune project hashtags a little more

Summary: Fixes T7738. Improves handling of question marks and quotation marks.

Test Plan: Unit tests.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7738

Differential Revision: https://secure.phabricator.com/D12265

src/applications/project/remarkup/ProjectRemarkupRule.php

@@ -30,7 +30,21 @@ final class ProjectRemarkupRule extends PhabricatorObjectRemarkupRule {
     // In other contexts, the PhabricatorProjectProjectPHIDType pattern is
     // controlling and these names should parse correctly.
 
-    return '[^\s.\d!,:;{}#\(\)]+(?:[^\s!,:;{}#\(\)]*[^\s.!,:;{}#\(\)]+)*';
+    // These characters may never appear anywhere in a hashtag.
+    $never = '\s?!,:;{}#\\(\\)"\'';
+
+    // These characters may not appear at the beginning.
+    $never_first = '.\d';
+
+    // These characters may not appear at the end.
+    $never_last = '.';
+
+    return
+      '[^'.$never_first.$never.']+'.
+      '(?:'.
+        '[^'.$never.']*'.
+        '[^'.$never_last.$never.']+'.
+      ')*';
   }
 
   protected function loadObjects(array $ids) {

src/applications/project/remarkup/__tests__/ProjectRemarkupRuleTestCase.php

@@ -81,6 +81,36 @@ final class ProjectRemarkupRuleTestCase extends PhabricatorTestCase {
         ),
       ),
 
+      'Is this #urgent?' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 9,
+            'id' => 'urgent',
+          ),
+        ),
+      ),
+
+      'This is "#urgent".' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 10,
+            'id' => 'urgent',
+          ),
+        ),
+      ),
+
+      'This is \'#urgent\'.' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 10,
+            'id' => 'urgent',
+          ),
+        ),
+      ),
+
     );
 
     foreach ($cases as $input => $expect) {