Bug 743877 - tab switching shouldn't occur off a timeout; r=gavin

toolkit/content/tests/chrome/test_tabbox.xul

@@ -183,15 +183,13 @@ function test_tabbox_focus()
   var tabbox = $("tabbox-nofocus");
   var tab = $("tab-nofocus");
 
-  tab.addEventListener("focus", function () {
-    tab.removeEventListener("focus", arguments.callee, true);
+  when_tab_focused(tab, function () {
     ok(document.activeElement, tab, "focus in tab with no focusable elements");
 
     tabbox.selectedIndex = 0;
     $("tab-nofocus-button").focus();
 
-    tab.addEventListener("focus", function () {
-      tab.removeEventListener("focus", arguments.callee, true);
+    when_tab_focused(tab, function () {
       ok(document.activeElement, tab, "focus in tab with no focusable elements, but with something in another tab focused");
 
       var textboxExtra = $("textbox-extra");
@@ -205,14 +203,21 @@ function test_tabbox_focus()
       tabbox.selectedIndex = 0;
       textboxExtra.hidden = false;
       synthesizeMouseAtCenter(tab, { });
-    }, true);
+    });
 
     synthesizeMouseAtCenter(tab, { });
-  }, true);
+  });
 
   synthesizeMouseAtCenter(tab, { });
 }
 
+function when_tab_focused(tab, callback) {
+  tab.addEventListener("focus", function onFocused() {
+    tab.removeEventListener("focus", onFocused, true);
+    SimpleTest.executeSoon(callback);
+  }, true);
+}
+
 ]]>
 </script>
 

toolkit/content/widgets/tabbox.xml

@@ -791,13 +791,23 @@
           return;
 
         if (this != this.parentNode.selectedItem) { // Not selected yet
-          // Select new tab after short delay so that PostHandleEvent() doesn't see
-          // the tab as selected yet, otherwise it will focus the tab for us --
-          // the CSS for tab has -moz-user-focus: normal only for selected="true".
-          function setTab(tab) {
-            tab.parentNode._selectNewTab(tab);
+          // Call this before setting the 'ignorefocus' attribute because this
+          // will pass on focus if the formerly selected tab was focused as well.
+          this.parentNode._selectNewTab(this);
+
+          var isTabFocused = false;
+          try {
+            isTabFocused = (document.commandDispatcher.focusedElement == this);
+          } catch (e) {}
+
+          // Set '-moz-user-focus' to 'ignore' so that PostHandleEvent() can't
+          // focus the tab; we only want tabs to be focusable by the mouse if
+          // they are already focused. After a short timeout we'll reset
+          // '-moz-user-focus' so that tabs can be focused by keyboard again.
+          if (!isTabFocused) {
+            this.setAttribute("ignorefocus", "true");
+            setTimeout(function (tab) tab.removeAttribute("ignorefocus"), 0, this);
           }
-          setTimeout(setTab, 0, this);
         }
         // Otherwise this tab is already selected and we will fall
         // through to mousedown behavior which sets focus on the current tab,

toolkit/content/xul.css

@@ -652,7 +652,7 @@ tab {
   -moz-box-pack: center;
 }
 
-tab[selected="true"] {
+tab[selected="true"]:not([ignorefocus="true"]) {
   -moz-user-focus: normal;
 }