updated drupal core to 7.51

misc/drupal.js

@@ -413,6 +413,29 @@ Drupal.getSelection = function (element) {
   return { 'start': element.selectionStart, 'end': element.selectionEnd };
 };
 
+/**
+ * Add a global variable which determines if the window is being unloaded.
+ *
+ * This is primarily used by Drupal.displayAjaxError().
+ */
+Drupal.beforeUnloadCalled = false;
+$(window).bind('beforeunload pagehide', function () {
+    Drupal.beforeUnloadCalled = true;
+});
+
+/**
+ * Displays a JavaScript error from an Ajax response when appropriate to do so.
+ */
+Drupal.displayAjaxError = function (message) {
+  // Skip displaying the message if the user deliberately aborted (for example,
+  // by reloading the page or navigating to a different page) while the Ajax
+  // request was still ongoing. See, for example, the discussion at
+  // http://stackoverflow.com/questions/699941/handle-ajax-error-when-a-user-clicks-refresh.
+  if (!Drupal.beforeUnloadCalled) {
+    alert(message);
+  }
+};
+
 /**
  * Build an error message from an Ajax response.
  */