Merge "wpUndidRevision should be passed along during 'preview' and 'diff'"

diff --combined includes/EditPage.php
index 61742c2,be1e75e..ec9f6ba
--- 1/includes/EditPage.php
--- 2/includes/EditPage.php
+++ b/includes/EditPage.php
@@@ -666,6 -666,11 +666,11 @@@ class EditPage 
                        $this->edittime = $request->getVal( 'wpEdittime' );
                        $this->starttime = $request->getVal( 'wpStarttime' );
  
+                       $undidRev = $request->getInt( 'wpUndidRevision' );
+                       if ( $undidRev ) {
+                               $this->undidRev = $undidRev;
+                       }
+ 
                        $this->scrolltop = $request->getIntOrNull( 'wpScrolltop' );
  
                        if ( $this->textbox1 === '' && $request->getVal( 'wpTextbox1' ) === null ) {
@@@ -1526,7 -1531,7 +1531,7 @@@
                        // message with content equivalent to default (allow empty pages
                        // in this case to disable messages, see bug 50124)
                        $defaultMessageText = $this->mTitle->getDefaultMessageText();
 -                      if( $this->mTitle->getNamespace() === NS_MEDIAWIKI && $defaultMessageText !== false ) {
 +                      if ( $this->mTitle->getNamespace() === NS_MEDIAWIKI && $defaultMessageText !== false ) {
                                $defaultText = $defaultMessageText;
                        } else {
                                $defaultText = '';