Bug 725996 - New Tab Page should not respond to dragged bookmark folders or should handle them properly; r=dietrich

browser/base/content/newtab/drag.js

@@ -106,7 +106,11 @@ let gDrag = {
    */
   isValid: function Drag_isValid(aEvent) {
     let dt = aEvent.dataTransfer;
-    return dt && dt.types.contains("text/x-moz-url");
+    let mimeType = "text/x-moz-url";
+
+    // Check that the drag data is non-empty.
+    // Can happen when dragging places folders.
+    return dt && dt.types.contains(mimeType) && dt.getData(mimeType);
   },
 
   /**

browser/base/content/test/newtab/Makefile.in

@@ -23,6 +23,7 @@ _BROWSER_FILES = \
 	browser_newtab_bug722273.js \
 	browser_newtab_bug723102.js \
 	browser_newtab_bug723121.js \
+	browser_newtab_bug725996.js \
 	browser_newtab_bug734043.js \
 	head.js \
 	$(NULL)

browser/base/content/test/newtab/browser_newtab_bug725996.js

@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function runTests() {
+  setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks("");
+
+  yield addNewTabPageTab();
+  checkGrid("0,1,2,3,4,5,6,7,8");
+
+  let cell = cells[0].node;
+
+  sendDropEvent(cell, "about:blank#99\nblank");
+  is(NewTabUtils.pinnedLinks.links[0].url, "about:blank#99",
+     "first cell is pinned and contains the dropped site");
+
+  yield whenPagesUpdated();
+  checkGrid("99p,0,1,2,3,4,5,6,7");
+
+  sendDropEvent(cell, "");
+  is(NewTabUtils.pinnedLinks.links[0].url, "about:blank#99",
+     "first cell is still pinned with the site we dropped before");
+}
+
+function sendDropEvent(aNode, aData) {
+  let ifaceReq = cw.QueryInterface(Ci.nsIInterfaceRequestor);
+  let windowUtils = ifaceReq.getInterface(Ci.nsIDOMWindowUtils);
+
+  let dataTransfer = {
+    mozUserCancelled: false,
+    setData: function () null,
+    setDragImage: function () null,
+    getData: function () aData,
+
+    types: {
+      contains: function (aType) aType == "text/x-moz-url"
+    },
+
+    mozGetDataAt: function (aType, aIndex) {
+      if (aIndex || aType != "text/x-moz-url")
+        return null;
+
+      return aData;
+    },
+  };
+
+  let event = cw.document.createEvent("DragEvents");
+  event.initDragEvent("drop", true, true, cw, 0, 0, 0, 0, 0,
+                      false, false, false, false, 0, null, dataTransfer);
+
+  windowUtils.dispatchDOMEventViaPresShell(aNode, event, true);
+}