Bug 594909 - Intermittent failure in browser/base/content/test/tabvie…

…w/browser_tabview_launch.js | Tab View is visible r=dietrich, a=test

browser/base/content/test/tabview/browser_tabview_launch.js

@@ -55,13 +55,28 @@ function test() {
 function onTabViewLoadedAndShown() {
   window.removeEventListener("tabviewshown", onTabViewLoadedAndShown, false);
 
-  ok(TabView.isVisible(), "Tab View is visible. Count: " + tabViewShownCount);
-  tabViewShownCount++;
+  // Evidently sometimes isVisible (which is based on the selectedIndex of the
+  // tabview deck) isn't updated immediately when called from button.doCommand,
+  // so we add a little timeout here to get outside of the doCommand call.
+  // If the initial timeout isn't enough, we keep waiting in case it's taking
+  // longer than expected.
+  // See bug 594909.
+  let deck = document.getElementById("tab-view-deck");
+  function waitForSwitch() {
+    if (deck.selectedIndex == 1) {
+      ok(TabView.isVisible(), "Tab View is visible. Count: " + tabViewShownCount);
+      tabViewShownCount++;
+
+      // kick off the series
+      window.addEventListener("tabviewshown", onTabViewShown, false);
+      window.addEventListener("tabviewhidden", onTabViewHidden, false);
+      TabView.toggle();
+    } else {
+      setTimeout(waitForSwitch, 10);
+    }
+  }
 
-  // kick off the series
-  window.addEventListener("tabviewshown", onTabViewShown, false);
-  window.addEventListener("tabviewhidden", onTabViewHidden, false);
-  TabView.toggle();
+  setTimeout(waitForSwitch, 1);
 }
 
 // ----------