fix(ngAnimate): don't normalize classes on follow-up animations to joined animations

This allows follow-up animations to remove a class that is currently
being added.

Fixes angular#13339
Fixes angular#13380
Closes angular#13414

Author: Narretz

src/ngAnimate/animateQueue.js

@@ -360,19 +360,15 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
           // so an example would involve a leave animation taking over an enter. Then when
           // the postDigest kicks in the enter will be ignored.
           var joinAnimationFlag = isAllowed('join', element, newAnimation, existingAnimation);
-          if (joinAnimationFlag) {
-            if (existingAnimation.state === RUNNING_STATE) {
-              normalizeAnimationOptions(element, options);
-            } else {
-              applyGeneratedPreparationClasses(element, isStructural ? event : null, options);
+          if (joinAnimationFlag && existingAnimation.state < RUNNING_STATE) {
+            applyGeneratedPreparationClasses(element, isStructural ? event : null, options);
 
-              event = newAnimation.event = existingAnimation.event;
-              options = mergeAnimationOptions(element, existingAnimation.options, newAnimation.options);
+            event = newAnimation.event = existingAnimation.event;
+            options = mergeAnimationOptions(element, existingAnimation.options, newAnimation.options);
 
-              //we return the same runner since only the option values of this animation will
-              //be fed into the `existingAnimation`.
-              return existingAnimation.runner;
-            }
+            //we return the same runner since only the option values of this animation will
+            //be fed into the `existingAnimation`.
+            return existingAnimation.runner;
           }
         }
       } else {

test/ngAnimate/integrationSpec.js

@@ -351,6 +351,44 @@ describe('ngAnimate integration tests', function() {
 
       dealoc(element);
     }));
+
+
+    it("should not normalize classes in a follow-up animation to a joined class-based animation",
+      inject(function($animate, $animateCss, $rootScope, $document, $rootElement, $$rAF) {
+
+      ss.addRule('.hide', 'opacity: 0');
+      ss.addRule('.hide-add, .hide-remove', 'transition: 1s linear all');
+
+      jqLite($document[0].body).append($rootElement);
+      element = jqLite('<div></div>');
+      $rootElement.append(element);
+
+      // These animations will be joined together
+      $animate.addClass(element, 'red');
+      $animate.addClass(element, 'hide');
+      $rootScope.$digest();
+
+      expect(element).toHaveClass('red-add');
+      expect(element).toHaveClass('hide-add');
+
+      // When a digest has passed, but no $rAF has been issued yet, .hide hasn't been added to
+      // the element, which means class normalization does not allow .hide to get removed
+      $animate.removeClass(element, 'hide');
+      $rootScope.$digest();
+      $$rAF.flush();
+
+      expect(element).toHaveClass('hide-remove hide-remove-active');
+
+      //End the animation process
+      browserTrigger(element, 'transitionend',
+        { timeStamp: Date.now() + 1000, elapsedTime: 2 });
+      $animate.flush();
+
+      expect(element).not.toHaveClass('hide-add-active red-add-active');
+      expect(element).toHaveClass('red');
+      expect(element).not.toHaveClass('hide');
+    }));
+
   });
 
   describe('JS animations', function() {