📰 Fix crash when tapping the menu on closed NTP

chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.ntp;
 
 import android.app.Activity;
 import android.support.annotation.IntDef;
 import android.support.annotation.StringRes;
+import android.support.v13.view.ViewCompat;
 import android.view.ContextMenu;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.MenuItem.OnMenuItemClickListener;
 import android.view.View;
 
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ntp.NewTabPageView.NewTabPageManager;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsConfig;
 import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
@@ skipping 53 matching lines @@
     }
 
     /**
      * Populates the context menu.
      * @param menu The menu to populate.
      * @param associatedView The view that requested a context menu.
      * @param delegate Delegate that defines the configuration of the menu and what to do when items
      *                 are tapped.
      */
     public void createContextMenu(ContextMenu menu, View associatedView, Delegate delegate) {
-        OnMenuItemClickListener listener = new ItemClickListener(delegate);
+        OnMenuItemClickListener listener = new ItemClickListener(delegate, associatedView);
         boolean hasItems = false;
 
         for (@ContextMenuItemId int itemId : MenuItemLabelMatcher.STRING_MAP.keySet()) {
             if (!shouldShowItem(itemId, delegate)) continue;
 
             @StringRes
             int itemString = MenuItemLabelMatcher.STRING_MAP.get(itemId);
             menu.add(Menu.NONE, itemId, Menu.NONE, itemString).setOnMenuItemClickListener(listener);
             hasItems = true;
         }
@@ skipping 66 matching lines @@
                 put(ID_OPEN_IN_NEW_TAB, R.string.contextmenu_open_in_new_tab);
                 put(ID_OPEN_IN_INCOGNITO_TAB, R.string.contextmenu_open_in_incognito_tab);
                 put(ID_SAVE_FOR_OFFLINE, R.string.contextmenu_save_link);
                 put(ID_REMOVE, R.string.remove);
             }
         };
     }
 
     private static class ItemClickListener implements OnMenuItemClickListener {
         private final Delegate mDelegate;
+        private final View mAssociatedView;
 
-        ItemClickListener(Delegate delegate) {
+        ItemClickListener(Delegate delegate, View associatedView) {
             mDelegate = delegate;
+            mAssociatedView = associatedView;
         }
 
         @Override
         public boolean onMenuItemClick(MenuItem item) {
+            // If the user clicks a snippet then immediately long presses they will create a context
+            // menu while the snippet's URL loads in the background. This means that when they press
+            // an item on context menu the NTP will not actually be open. We add this check here to
+            // prevent taking any action if the user has left the NTP. (https://crbug.com/640468)
+            // Although the menu is supposed to be closed when we navigate away from the NTP, we
+            // have to keep this check because of race conditions. (https://crbug.com/668945)
+            if (!ViewCompat.isAttachedToWindow(mAssociatedView)) return true;
+
             switch (item.getItemId()) {
                 case ID_OPEN_IN_NEW_WINDOW:
                     mDelegate.openItem(WindowOpenDisposition.NEW_WINDOW);
                     return true;
                 case ID_OPEN_IN_NEW_TAB:
                     mDelegate.openItem(WindowOpenDisposition.NEW_FOREGROUND_TAB);
                     return true;
                 case ID_OPEN_IN_INCOGNITO_TAB:
                     mDelegate.openItem(WindowOpenDisposition.OFF_THE_RECORD);
                     return true;
                 case ID_SAVE_FOR_OFFLINE:
                     mDelegate.openItem(WindowOpenDisposition.SAVE_TO_DISK);
                     return true;
                 case ID_REMOVE:
                     mDelegate.removeItem();
                     return true;
                 default:
                     return false;
             }
         }
     }
 }