fix(dialog): make sure dialog only destroys itself.

Dialog destruction is async and deferred. As such, there's a risk of another dialog having been created by the time the current dialog's "destroy()" is called.

*  Added tests for testing dialog double opening.
*  Fix a bug which prevents a dialog from being closed if it's opened while another dialog is shown.

Closes #5157.

src/components/dialog/dialog.js

@@ -27,7 +27,7 @@ function MdDialogDirective($$rAF, $mdTheming, $mdDialog) {
         }
 
         scope.$on('$destroy', function() {
-          $mdDialog.destroy();
+          $mdDialog.destroy(element);
         });
 
         /**

src/components/dialog/dialog.spec.js

@@ -970,6 +970,65 @@ describe('$mdDialog', function() {
       expect(parent[0].querySelectorAll('md-dialog.two').length).toBe(1);
     }));
 
+    it('should hide dialog', inject(function($mdDialog, $rootScope, $animate) {
+      var parent = angular.element('<div>');
+      $mdDialog.show({
+        template: '<md-dialog class="one">',
+        parent: parent
+      });
+      runAnimation();
+
+      $mdDialog.hide();
+      runAnimation();
+
+      expect(parent[0].querySelectorAll('md-dialog.one').length).toBe(0);
+    }));
+
+    it('should allow opening new dialog after existing without corruption', inject(function($mdDialog, $rootScope, $animate) {
+      var parent = angular.element('<div>');
+      $mdDialog.show({
+        template: '<md-dialog class="one">',
+        parent: parent
+      });
+      runAnimation();
+      $mdDialog.hide();
+      runAnimation();
+
+      $mdDialog.show({
+        template: '<md-dialog class="two">',
+        parent: parent
+      });
+      runAnimation();
+      $mdDialog.hide();
+      runAnimation();
+
+      expect(parent[0].querySelectorAll('md-dialog.one').length).toBe(0);
+      expect(parent[0].querySelectorAll('md-dialog.two').length).toBe(0);
+    }));
+
+    it('should allow opening new dialog from existing without corruption', inject(function($mdDialog, $rootScope, $animate) {
+      var parent = angular.element('<div>');
+      $mdDialog.show({
+        template: '<md-dialog class="one">',
+        parent: parent
+      });
+      runAnimation();
+
+      $mdDialog.show({
+        template: '<md-dialog class="two">',
+        parent: parent
+      });
+      //First run is for the old dialog being hidden.
+      runAnimation();
+      //Second run is for the new dialog being shown.
+      runAnimation();
+      $mdDialog.hide();
+      runAnimation();
+
+      expect(parent[0].querySelectorAll('md-dialog.one').length).toBe(0);
+      expect(parent[0].querySelectorAll('md-dialog.two').length).toBe(0);
+    }));
+
     it('should have the dialog role', inject(function($mdDialog, $rootScope) {
       var template = '<md-dialog>Hello</md-dialog>';
       var parent = angular.element('<div>');
@@ -1141,4 +1200,3 @@ describe('$mdDialog with custom interpolation symbols', function() {
     expect(buttons.eq(1).text()).toBe('OK');
   }));
 });
-

src/core/services/interimElement/interimElement.js

@@ -370,14 +370,29 @@ function InterimElementProvider() {
 
       /*
        * Special method to quick-remove the interim element without animations
+       * Note: interim elements are in "interim containers"
        */
-      function destroy() {
-        var interim = stack.shift();
+      function destroy(target) {
+        var interim = !target ? stack.shift() : null;
+        var cntr = angular.element(target).length ? angular.element(target)[0].parentNode : null;
+
+        if (cntr) {
+            // Try to find the interim element in the stack which corresponds to the supplied DOM element.
+            var filtered = stack.filter(function(entry) {
+                  var currNode = entry.options.element[0];
+                  return  (currNode === cntr);
+                });
 
-        return interim ? interim.remove(SHOW_CANCELLED, false, {'$destroy':true}) :
-               $q.when(SHOW_CANCELLED);
-      }
+            // Note: this function might be called when the element already has been removed, in which
+            //       case we won't find any matches. That's ok.
+            if (filtered.length > 0) {
+              interim = filtered[0];
+              stack.splice(stack.indexOf(interim), 1);
+            }
+        }
 
+        return interim ? interim.remove(SHOW_CANCELLED, false, {'$destroy':true}) : $q.when(SHOW_CANCELLED);
+      }
 
       /*
        * Internal Interim Element Object
@@ -438,7 +453,9 @@ function InterimElementProvider() {
 
           if ( options.$destroy === true ) {
 
-            return hideElement(options.element, options);
+            return hideElement(options.element, options).then(function(){
+              (isCancelled && rejectAll(response)) || resolveAll(response);
+            });
 
           } else {