Fix a content join condition in Phriction

After the cursor changes, we may fatal on pages with a large number of children
because "c.title" is not a selected column. We currently join the "content"
table if "updated" is part of the order vector, but not if "title" is part of
the order vector. This isn't right: "updated" is on the primary table, and only
"content" is on the joined table.

src/applications/phriction/query/PhrictionDocumentQuery.php

@@ -193,7 +193,11 @@ final class PhrictionDocumentQuery
   }
 
   private function shouldJoinContentTable() {
-    return $this->getOrderVector()->containsKey('updated');
+    if ($this->getOrderVector()->containsKey('title')) {
+      return true;
+    }
+
+    return false;
   }
 
   protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {