Introduce $wgBetterDirectionality that lets us work on support for rtl ui in ltr wiki and vice versa.

includes/DefaultSettings.php

@@ -2282,6 +2282,12 @@ $wgVectorExtraStyles = null;
  */
 $wgEdititis = false;
 
+/**
+ * Experimental better directionality support.
+ */
+$wgBetterDirectionality = false;
+
+
 /** @} */ # End of output format settings }
 
 /*************************************************************************//**

includes/GlobalFunctions.php

@@ -561,6 +561,11 @@ function wfGetLangObj( $langcode = false ) {
 	return $wgContLang;
 }
 
+function wfUILang() {
+	global $wgBetterDirectionality;
+	return wfGetLangObj( $wgBetterDirectionality ? false: true );
+}
+
 /**
  * Get a message from anywhere, for the current user language.
  *

includes/Html.php

@@ -609,7 +609,10 @@ class Html {
 				$attribs["xmlns:$tag"] = $ns;
 			}
 		}
-		return $ret . Html::openElement( 'html', $attribs ) . "\n";
+		$html = Html::openElement( 'html', $attribs );
+		if ( $html ) $html .= "\n";
+		$ret .= $html;
+		return $ret;
 	}
 
 	/**

includes/OutputPage.php

@@ -2099,9 +2099,7 @@ class OutputPage {
 		}
 		$sk->setupUserCss( $this );
 
-		$dir = $wgContLang->getDir();
-		$htmlAttribs = array( 'lang' => $wgContLanguageCode, 'dir' => $dir );
-		$ret = Html::htmlHeader( $htmlAttribs );
+		$ret = Html::htmlHeader( array( 'lang' => wfUILang()->getCode() ) );
 
 		if ( $this->getHTMLTitle() == '' ) {
 			$this->setHTMLTitle( wfMsg( 'pagetitle', $this->getPageTitle() ) );
@@ -2156,6 +2154,7 @@ class OutputPage {
 		}
 
 		# Class bloat
+		$dir = wfUILang()->getDir();
 		$bodyAttrs['class'] = "mediawiki $dir";
 
 		if ( $wgLang->capitalizeAllNouns() ) {
@@ -2427,8 +2426,7 @@ class OutputPage {
 	 */
 	protected function styleLink( $style, $options ) {
 		if( isset( $options['dir'] ) ) {
-			global $wgContLang;
-			$siteDir = $wgContLang->getDir();
+			$siteDir = wfUILang()->getDir();
 			if( $siteDir != $options['dir'] ) {
 				return '';
 			}

includes/SkinTemplate.php

@@ -297,9 +297,12 @@ class SkinTemplate extends Skin {
 		$tpl->setRef( 'scriptpath', $wgScriptPath );
 		$tpl->setRef( 'serverurl', $wgServer );
 		$tpl->setRef( 'logopath', $wgLogo );
-		$tpl->setRef( 'lang', $wgContLanguageCode );
-		$tpl->set( 'dir', $wgContLang->getDir() );
-		$tpl->set( 'rtl', $wgContLang->isRTL() );
+
+		$lang = wfUILang();
+		$tpl->set( 'lang', $lang->getCode() );
+		$tpl->set( 'dir', $lang->getDir() );
+		$tpl->set( 'rtl', $lang->isRTL() );
+
 		$tpl->set( 'capitalizeallnouns', $wgLang->capitalizeAllNouns() ? ' capitalize-all-nouns' : '' );
 		$tpl->set( 'showjumplinks', $wgUser->getOption( 'showjumplinks' ) );
 		$tpl->set( 'username', $wgUser->isAnon() ? null : $this->username );
@@ -415,6 +418,11 @@ class SkinTemplate extends Skin {
 		$tpl->set( 'bottomscripts', $this->bottomScripts() );
 
 		$printfooter = "<div class=\"printfooter\">\n" . $this->printSource() . "</div>\n";
+		global $wgBetterDirectionality;
+		if ( $wgBetterDirectionality ) {
+			$realBodyAttribs = array( 'lang' => $wgContLanguageCode, 'dir' => $wgContLang->getDir() );
+			$out->mBodytext = Html::rawElement( 'div', $realBodyAttribs, $out->mBodytext );
+		}
 		$out->mBodytext .= $printfooter . $this->generateDebugHTML();
 		$tpl->setRef( 'bodytext', $out->mBodytext );
 

skins/Vector.php

@@ -682,7 +682,7 @@ class VectorTemplate extends QuickTemplate {
 		if ( !is_array( $elements ) ) {
 			$elements = array( $elements );
 		// If there's a series of elements, reverse them when in RTL mode
-		} else if ( $wgContLang->isRTL() ) {
+		} else if ( wfUILang()->isRTL() ) {
 			$elements = array_reverse( $elements );
 		}
 		// Render elements