Bug 249136. Focus lost when key pressed in newly loading foreground tab. r=mconnor, a=mconnor

toolkit/content/widgets/tabbrowser.xml

@@ -1352,8 +1352,12 @@
         </getter>
         <setter>
           <![CDATA[
-          // Update the tab
+            // Set newly selected tab after quick timeout, otherwise hideous focus problems
-          this.mTabBox.selectedTab = val;
+            // can occur when "browser.tabs.loadInBackground" is false and presshell is not ready
+            function setTab(tabBox, tab) {
+              tabBox.selectedTab = tab;
+            }
+            setTimeout(setTab, 0, this.mTabBox, val);
             return val;
           ]]>
         </setter>