diff --git a/core/misc/drupal.js b/core/misc/drupal.js
index 458d385..f49aef0 100644
--- a/core/misc/drupal.js
+++ b/core/misc/drupal.js
@@ -17,27 +17,7 @@ if (window.jQuery) {
 
   "use strict";
 
-  /**
-   * Custom error type thrown after attach/detach if one or more behaviors failed.
-   *
-   * @param list
-   *   An array of errors thrown during attach/detach.
-   * @param event
-   *   A string containing either 'attach' or 'detach'.
-   */
-  function DrupalBehaviorError(list, event) {
-    this.name = 'DrupalBehaviorError';
-    this.event = event || 'attach';
-    this.list = list;
-    // Makes the list of errors readable.
-    var messageList = [];
-    messageList.push(this.event);
-    for (var i = 0, il = this.list.length; i < il; i++) {
-      messageList.push(this.list[i].behavior + ': ' + this.list[i].error.message);
-    }
-    this.message = messageList.join(' ; ');
-  }
-  DrupalBehaviorError.prototype = new Error();
+  var behaviors_done = [];
 
   /**
    * Attach all registered behaviors to a page element.
@@ -80,23 +60,34 @@ if (window.jQuery) {
   Drupal.attachBehaviors = function (context, settings) {
     context = context || document;
     settings = settings || drupalSettings;
-    var i, errors = [], behaviors = Drupal.behaviors;
+    var i, errorThrown, behaviors = Drupal.behaviors;
     // Execute all of them.
     for (i in behaviors) {
-      if (behaviors.hasOwnProperty(i) && typeof behaviors[i].attach === 'function') {
-        // Don't stop the execution of behaviors in case of an error.
+      if (behaviors.hasOwnProperty(i) && typeof behaviors[i].attach === 'function' && behaviors_done.indexOf(i) === -1) {
+        // Catching errors makes debugging more difficult, so we start with
+        // errorThrown set to true before setting it to false after calling
+        // the behavior -- if it's still set to true in the finally block, it
+        // means the behavior threw.
+        errorThrown = true;
         try {
           behaviors[i].attach(context, settings);
-        }
-        catch (e) {
-          errors.push({ behavior: i, error: e });
+          errorThrown = false;
+        } finally {
+          behaviors_done.push(i);
+          if (errorThrown) {
+            // The behavior i threw an error; execute the remaining
+            // behaviors but silence any exceptions from them to ensure that
+            // the first error is the one to bubble up.
+            try {
+              Drupal.attachBehaviors(context, settings);
+            } catch (e) {
+            }
+          }
         }
       }
     }
-    // Once all behaviors have been processed, inform the user about errors.
-    if (errors.length) {
-      throw new DrupalBehaviorError(errors, 'attach');
-    }
+    // reset it
+    behaviors_done = [];
   };
 
   // Attach all behaviors.