diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug625269.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug625269.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,76 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+  newWindowWithTabView(onTabViewShown, null, 850);
+}
+
+function onTabViewShown(win) {
+  registerCleanupFunction(function () win.close());
+
+  let contentWindow = win.TabView.getContentWindow();
+  let currentGroup = contentWindow.GroupItems.getActiveGroupItem();
+
+  function checkResized(diffX, diffY, shouldResize, text, callback) {
+    let {width: origWidth, height: origHeight} = currentGroup.getBounds();
+
+    resizeWindow(win, diffX, diffY, function () {
+      let {width: newWidth, height: newHeight} = currentGroup.getBounds();
+      let resized = (origWidth != newWidth || origHeight != newHeight);
+
+      is(resized, shouldResize, text + ": The group should " +
+         (shouldResize ? "" : "not ") + "have been resized");
+
+      callback();
+    });
+  }
+
+  function next() {
+    let test = tests.shift();
+
+    if (test)
+      checkResized.apply(this, test.concat([next]));
+    else
+      finishTest();
+  }
+
+  function finishTest() {
+    // reset the usersize of the group, so this should clear the "cramped" feeling.
+    currentGroup.setSize(100, 100, true);
+    currentGroup.setUserSize();
+    checkResized(400, 400, false, "After clearing the cramp", finish);
+  }
+
+  let tests = [
+    // diffX, diffY, shouldResize, text
+    [ -50,  -50, false, "A little smaller"],
+    [  50,   50, false, "A little bigger"],
+    [-400, -400, true,  "Much smaller"],
+    [ 400,  400, true,  "Bigger after much smaller"],
+    [-400, -400, true,  "Much smaller"]
+  ];
+
+  // setup
+  currentGroup.setSize(600, 600, true);
+  currentGroup.setUserSize();
+
+  // run the tests
+  next();
+}
+
+// ----------
+function resizeWindow(win, diffX, diffY, callback) {
+  let targetWidth = win.outerWidth + diffX;
+  let targetHeight = win.outerHeight + diffY;
+
+  (function tryResize() {
+    let {outerWidth: width, outerHeight: height} = win;
+    if (width != targetWidth || height != targetHeight) {
+      win.resizeTo(targetWidth, targetHeight);
+      executeSoon(tryResize);
+    } else {
+      callback();
+    }
+  })();
+}