Merge "Fix IE9's lack of support for console.warn.apply"

diff --combined resources/src/mediawiki/mediawiki.js
index 1591a94,e844f95..3025260
--- 1/resources/src/mediawiki/mediawiki.js
--- 2/resources/src/mediawiki/mediawiki.js
+++ b/resources/src/mediawiki/mediawiki.js
@@@ -471,7 -471,7 +471,7 @@@ var mw = ( function ( $, undefined ) 
                 *
                 * This was reserved for future use but never ended up being used.
                 *
 -               * @deprecated since 1.22: Let deprecated identifiers keep their original name
 +               * @deprecated since 1.22 Let deprecated identifiers keep their original name
                 *  and use mw.log#deprecate to create an access container for tracking.
                 * @property
                 */
@@@ -538,7 -538,7 +538,7 @@@
                         */
                        log.warn = function () {
                                var console = window.console;
-                               if ( console && console.warn ) {
+                               if ( console && console.warn && console.warn.apply ) {
                                        console.warn.apply( console, arguments );
                                        if ( console.trace ) {
                                                console.trace();