From 2cd09c9f0e7766bcd191662841b7b1ffc3b6dc3f Mon Sep 17 00:00:00 2001
From: Noam Lewis <jones.noamle@gmail.com>
Date: Mon, 30 Dec 2013 20:10:23 -0500
Subject: [PATCH] fix($rootScope): prevent infinite $digest by checking if
 asyncQueue is empty when decrementing ttl

An infinite $digest loop can be caused by expressions that invoke a promise.
The problem is that $digest does not decrement ttl unless it finds dirty changes;
it should check also if asyncQueue is empty.
Generally the condition for decrementing ttl should be the same as the
condition for terminating the $digest loop.

Fixes #2622
---
 src/ng/rootScope.js      |  2 +-
 test/ng/rootScopeSpec.js | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/ng/rootScope.js b/src/ng/rootScope.js
index 8259bf881bd9..bbf290b2909a 100644
--- a/src/ng/rootScope.js
+++ b/src/ng/rootScope.js
@@ -632,7 +632,7 @@ function $RootScopeProvider(){
 
           // `break traverseScopesLoop;` takes us to here
 
-          if(dirty && !(ttl--)) {
+          if((dirty || asyncQueue.length) && !(ttl--)) {
             clearPhase();
             throw $rootScopeMinErr('infdig',
                 '{0} $digest() iterations reached. Aborting!\n' +
diff --git a/test/ng/rootScopeSpec.js b/test/ng/rootScopeSpec.js
index e47111e2d0eb..f9cf9412c605 100644
--- a/test/ng/rootScopeSpec.js
+++ b/test/ng/rootScopeSpec.js
@@ -258,6 +258,31 @@ describe('Scope', function() {
     }));
 
 
+    it('should prevent infinite loop when creating and resolving a promise in a watched expression', function() {
+      module(function($rootScopeProvider) {
+          $rootScopeProvider.digestTtl(10);
+      });
+      inject(function($rootScope, $q) {
+          var d = $q.defer();
+
+          d.resolve('Hello, world.');
+          $rootScope.$watch(function () {
+              var $d2 = $q.defer();
+              $d2.resolve('Goodbye.');
+              $d2.promise.then(function () { });
+              return d.promise;
+          }, function () { return 0; });
+
+          expect(function() {
+              $rootScope.$digest();
+          }).toThrowMinErr('$rootScope', 'infdig', '10 $digest() iterations reached. Aborting!\n'+
+                  'Watchers fired in the last 5 iterations: []');
+
+          expect($rootScope.$$phase).toBeNull();
+      });
+      });
+
+
     it('should not fire upon $watch registration on initial $digest', inject(function($rootScope) {
       var log = '';
       $rootScope.a = 1;