Merge "Add actual documentation for ContentHandler::getActionOverrides"

diff --combined includes/actions/Action.php
index 4208b3b,84bf16e..ae4c6d6
--- 1/includes/actions/Action.php
--- 2/includes/actions/Action.php
+++ b/includes/actions/Action.php
@@@ -62,7 -62,7 +62,7 @@@ abstract class Action 
         * the action is disabled, or null if it's not recognised
         * @param string $action
         * @param array $overrides
-        * @return bool|null|string|callable
+        * @return bool|null|string|callable|Action
         */
        final private static function getClass( $action, array $overrides ) {
                global $wgActions;
@@@ -147,7 -147,7 +147,7 @@@
                // Trying to get a WikiPage for NS_SPECIAL etc. will result
                // in WikiPage::factory throwing "Invalid or virtual namespace -1 given."
                // For SpecialPages et al, default to action=view.
 -              if ( !$context->canUseWikiPage() ) {
 +              if ( $actionName === '' || !$context->canUseWikiPage() ) {
                        return 'view';
                }