Merge pull request #2866 from LeoUnglaub/master

Fixing issue #2864

select2.js

@@ -1943,7 +1943,7 @@ the specific language governing permissions and limitations under the Apache Lic
                 } else if (this.opts.width === "copy" || this.opts.width === "resolve") {
                     // check if there is inline style on the element that contains width
                     style = this.opts.element.attr('style');
-                    if (style !== undefined) {
+                    if (typeof(style) === "string") {
                         attrs = style.split(';');
                         for (i = 0, l = attrs.length; i < l; i = i + 1) {
                             attr = attrs[i].replace(/\s/g, '');