context: Support setting title to null

We have various entry points without a title set:

* load.php: Setup.php defaults $wgTitle to null. When messages
  are parsed, MessageCache::parse() will emit a warning and uses
  $wgTitle which is then casted to Special:Badtitle.

* Parser tests: Work all with context now (or parser options)
  without ever setting $wgTitle. However, in order to allow SpecialPageFactory
  to getTitle() and then setTitle() the same value from context, context needs
  to support setting null as title, the same way it can get null as title.

Change-Id: I770f449fe67beedc3f7d4009ed2208e9dde4491c

diff --git a/includes/context/RequestContext.php b/includes/context/RequestContext.php
index 35ee1b7..c8b8108 100644 (file)
--- a/includes/context/RequestContext.php
+++ b/includes/context/RequestContext.php
@@ -167,7 +167,7 @@ class RequestContext implements IContextSource, MutableContext {
         *
         * @param Title $title
         */
-       public function setTitle( Title $title ) {
+       public function setTitle( Title $title = null ) {
                $this->title = $title;
                // Erase the WikiPage so a new one with the new title gets created.
                $this->wikipage = null;