Bug 880101 - part 1 - Add test that forces the gBrowser constructor a little too early; r=gavin

browser/base/content/test/Makefile.in

@@ -184,6 +184,7 @@ MOCHITEST_BROWSER_FILES = \
                  browser_bug822367.js \
                  browser_bug832435.js \
                  browser_bug839103.js \
+                 browser_bug880101.js \
                  browser_bug882977.js \
                  browser_bug887515.js \
                  browser_canonizeURL.js \

browser/base/content/test/browser_bug880101.js

@@ -0,0 +1,50 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const URL = "about:robots";
+
+function test() {
+  let win;
+
+  let listener = {
+    onLocationChange: (webProgress, request, uri, flags) => {
+      ok(webProgress.isTopLevel, "Received onLocationChange from top frame");
+      is(uri.spec, URL, "Received onLocationChange for correct URL");
+      finish();
+    }
+  };
+
+  waitForExplicitFinish();
+
+  // Remove the listener and window when we're done.
+  registerCleanupFunction(() => {
+    win.gBrowser.removeProgressListener(listener);
+    win.close();
+  });
+
+  // Wait for the newly opened window.
+  whenNewWindowOpened(w => win = w);
+
+  // Open a link in a new window.
+  openLinkIn(URL, "window", {});
+
+  // On the next tick, but before the window has finished loading, access the
+  // window's gBrowser property to force the tabbrowser constructor early.
+  (function tryAddProgressListener() {
+    executeSoon(() => {
+      try {
+        win.gBrowser.addProgressListener(listener);
+      } catch (e) {
+        // win.gBrowser wasn't ready, yet. Try again in a tick.
+        tryAddProgressListener();
+      }
+    });
+  })();
+}
+
+function whenNewWindowOpened(cb) {
+  Services.obs.addObserver(function obs(win) {
+    Services.obs.removeObserver(obs, "domwindowopened");
+    cb(win);
+  }, "domwindowopened", false);
+}