diff -r 000000000000 -r 6474c204b198 browser/base/content/test/general/browser_tabDrop.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/general/browser_tabDrop.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,71 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  let newTab = gBrowser.selectedTab = gBrowser.addTab("about:blank", {skipAnimation: true});
+  registerCleanupFunction(function () {
+    gBrowser.removeTab(newTab);
+  });
+
+  let scriptLoader = Cc["@mozilla.org/moz/jssubscript-loader;1"].
+                     getService(Ci.mozIJSSubScriptLoader);
+  let ChromeUtils = {};
+  scriptLoader.loadSubScript("chrome://mochikit/content/tests/SimpleTest/ChromeUtils.js", ChromeUtils);
+
+  let tabContainer = gBrowser.tabContainer;
+  var receivedDropCount = 0;
+  function dropListener() {
+    receivedDropCount++;
+    if (receivedDropCount == triggeredDropCount) {
+      is(openedTabs, validDropCount, "correct number of tabs were opened");
+      executeSoon(finish);
+    }
+  }
+  tabContainer.addEventListener("drop", dropListener, false);
+  registerCleanupFunction(function () {
+    tabContainer.removeEventListener("drop", dropListener, false);
+  });
+
+  var openedTabs = 0;
+  function tabOpenListener(e) {
+    openedTabs++;
+    let tab = e.target;
+    executeSoon(function () {
+      gBrowser.removeTab(tab);
+    });
+  }
+
+  tabContainer.addEventListener("TabOpen", tabOpenListener, false);
+  registerCleanupFunction(function () {
+    tabContainer.removeEventListener("TabOpen", tabOpenListener, false);
+  });
+
+  var triggeredDropCount = 0;
+  var validDropCount = 0;
+  function drop(text, valid) {
+    triggeredDropCount++;
+    if (valid)
+      validDropCount++;
+    executeSoon(function () {
+      // A drop type of "link" onto an existing tab would normally trigger a
+      // load in that same tab, but tabbrowser code in _getDragTargetTab treats
+      // drops on the outer edges of a tab differently (loading a new tab
+      // instead). The events created by synthesizeDrop have all of their
+      // coordinates set to 0 (screenX/screenY), so they're treated as drops
+      // on the outer edge of the tab, thus they open new tabs.
+      ChromeUtils.synthesizeDrop(newTab, newTab, [[{type: "text/plain", data: text}]], "link", window);
+    });
+  }
+
+  // Begin and end with valid drops to make sure we wait for all drops before
+  // ending the test
+  drop("mochi.test/first", true);
+  drop("javascript:'bad'");
+  drop("jAvascript:'bad'");
+  drop("search this", true);
+  drop("mochi.test/second", true);
+  drop("data:text/html,bad");
+  drop("mochi.test/third", true);
+}