Fix PhabricatorProjectCustomFields to use storage correctly.

Summary: Prevents infinite recursion when trying to save custom fields on projects.

Test Plan: Add a custom field (that is a class, not one configured in the UI) to a project, and try to save it.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Projects: #phabricator

Maniphest Tasks: T5606

Differential Revision: https://secure.phabricator.com/D9908

src/applications/project/customfield/PhabricatorProjectCustomField.php

@@ -3,5 +3,16 @@
 abstract class PhabricatorProjectCustomField
   extends PhabricatorCustomField {
 
+  public function newStorageObject() {
+    return new PhabricatorProjectCustomFieldStorage();
+  }
+
+  protected function newStringIndexStorage() {
+    return new PhabricatorProjectCustomFieldStringIndex();
+  }
+
+  protected function newNumericIndexStorage() {
+    return new PhabricatorProjectCustomFieldNumericIndex();
+  }
 
 }