fix(tooltip): prevent opening when tooltipPopupDelay is present

- Cancel the timeout when `tooltipPopupDelay` is present and the element with the tooltip directive becomes disabled

Closes #4098
Fixes #3611

src/tooltip/test/tooltip.spec.js

@@ -260,7 +260,7 @@ describe('tooltip', function() {
     beforeEach(inject(function ($compile) {
       scope.delay='1000';
       elm = $compile(angular.element(
-        '<span tooltip="tooltip text" tooltip-popup-delay="{{delay}}">Selector Text</span>'
+        '<span tooltip="tooltip text" tooltip-popup-delay="{{delay}}" ng-disabled="disabled">Selector Text</span>'
       ))(scope);
       elmScope = elm.scope();
       tooltipScope = elmScope.$$childTail;
@@ -293,6 +293,19 @@ describe('tooltip', function() {
       expect(tooltipScope.isOpen).toBe(true);
     });
 
+    it('should not open if disabled is present', inject(function($timeout) {
+      elm.trigger('mouseenter');
+      expect(tooltipScope.isOpen).toBe(false);
+
+      $timeout.flush(500);
+      expect(tooltipScope.isOpen).toBe(false);
+      elmScope.disabled = true;
+      elmScope.$digest();
+
+      $timeout.flush();
+      expect(tooltipScope.isOpen).toBe(false);
+    }));
+
   });
 
   describe( 'with a trigger attribute', function() {

src/tooltip/tooltip.js

@@ -299,6 +299,10 @@ angular.module( 'ui.bootstrap.tooltip', [ 'ui.bootstrap.position', 'ui.bootstrap
             }
 
             attrs.$observe( 'disabled', function ( val ) {
+              if (popupTimeout && val) {
+                $timeout.cancel(popupTimeout);
+              }
+
               if (val && ttScope.isOpen ) {
                 hide();
               }