Bug 734043 - Error: node.parentNode is null when I click x button of thumbnail quickly in newTab page; r=dietrich

browser/base/content/newtab/sites.js

@@ -82,12 +82,17 @@ Site.prototype = {
   /**
    * Blocks the site (removes it from the grid) and calls the given callback
    * when done.
-   * @param aCallback The callback to be called when finished.
+   * @param aCallback The function to be called when finished.
    */
   block: function Site_block(aCallback) {
-    gBlockedLinks.block(this._link);
-    gUpdater.updateGrid(aCallback);
-    gPage.updateModifiedFlag();
+    if (gBlockedLinks.isBlocked(this._link)) {
+      if (aCallback)
+        aCallback();
+    } else {
+      gBlockedLinks.block(this._link);
+      gUpdater.updateGrid(aCallback);
+      gPage.updateModifiedFlag();
+    }
   },
 
   /**

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_bug734043.js \
 	head.js \
 	$(NULL)
 

browser/base/content/test/newtab/browser_newtab_bug734043.js

@@ -0,0 +1,27 @@
+/* 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();
+
+  let receivedError = false;
+  let block = cw.document.querySelector(".strip-button-block");
+
+  function onError() {
+    receivedError = true;
+  }
+
+  cw.addEventListener("error", onError);
+
+  for (let i = 0; i < 3; i++) {
+    EventUtils.synthesizeMouseAtCenter(block, {}, cw);
+    yield executeSoon(TestRunner.next);
+  }
+
+  yield whenPagesUpdated();
+  ok(!receivedError, "we got here without any errors");
+  cw.removeEventListener("error", onError);
+}

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

@@ -265,3 +265,15 @@ function simulateDrop(aDropTarget, aDragSource) {
   if (aDragSource)
     cw.gDrag.end(aDragSource.site);
 }
+
+/**
+ * Resumes testing when all pages have been updated.
+ */
+function whenPagesUpdated() {
+  NewTabUtils.allPages.register({
+    update: function () {
+      NewTabUtils.allPages.unregister(this);
+      executeSoon(TestRunner.next);
+    }
+  });
+}