fix race condition on list cleanup

packages/spark/spark.js

@@ -865,8 +865,10 @@ Spark.list = function (cursor, itemFunc, elseFunc) {
     }
   }
   initialContents = null; // save memory
+  var stopped = false;
   var cleanup = function () {
     handle.stop();
+    stopped = true;
   };
   html = annotate(html, Spark._ANNOTATION_LIST, function (range) {
     outerRange = range;
@@ -894,10 +896,17 @@ Spark.list = function (cursor, itemFunc, elseFunc) {
       walk.rendered.call(walk.landmark);
   };
 
+  var later = function (f) {
+    atFlushTime(function () {
+      if (! stopped)
+        f();
+    });
+  };
+
   // The DOM update callbacks.
   _.extend(callbacks, {
     added: function (item, beforeIndex) {
-      atFlushTime(function () {
+      later(function () {
         var frag = Spark.render(_.bind(itemFunc, null, item));
         DomUtils.wrapFragmentForContainer(frag, outerRange.containerNode());
         var range = new LiveRange(Spark._TAG, frag);
@@ -915,7 +924,7 @@ Spark.list = function (cursor, itemFunc, elseFunc) {
     },
 
     removed: function (item, atIndex) {
-      atFlushTime(function () {
+      later(function () {
         if (itemRanges.length === 1) {
           var frag = Spark.render(elseFunc);
           DomUtils.wrapFragmentForContainer(frag, outerRange.containerNode());
@@ -930,7 +939,7 @@ Spark.list = function (cursor, itemFunc, elseFunc) {
     },
 
     moved: function (item, oldIndex, newIndex) {
-      atFlushTime(function () {
+      later(function () {
         if (oldIndex === newIndex)
           return;
 
@@ -948,7 +957,7 @@ Spark.list = function (cursor, itemFunc, elseFunc) {
     },
 
     changed: function (item, atIndex) {
-      atFlushTime(function () {
+      later(function () {
         Spark.renderToRange(itemRanges[atIndex], _.bind(itemFunc, null, item));
       });
     }

packages/spark/spark_tests.js

@@ -3526,3 +3526,50 @@ Tinytest.add("spark - unique label", function (test) {
   test.equal(bufstr(), 'ddd');
 
 });
+
+Tinytest.add("spark - list update", function (test) {
+  var R = ReactiveVar('foo');
+
+  var lst = [];
+  lst.callbacks = [];
+  lst.observe = function(callbacks) {
+    lst.callbacks.push(callbacks);
+    _.each(lst, function(x, i) {
+      callbacks.added(x, i);
+    });
+    return {
+      stop: function() {
+        lst.callbacks = _.without(lst.callbacks, callbacks);
+      }
+    };
+  };
+  lst.another = function () {
+    var i = lst.length;
+    lst.push({_id:'item'+i});
+    _.each(lst.callbacks, function (callbacks) {
+      callbacks.added(lst[i], i);
+    });
+  };
+  var div = OnscreenDiv(Meteor.render(function() {
+    return R.get() + Spark.list(lst, function () {
+      return '<hr>';
+    });
+  }));
+
+  lst.another();
+  Meteor.flush();
+  test.equal(div.html(), "foo<hr>");
+
+  lst.another();
+  R.set('bar');
+  Meteor.flush();
+  test.equal(div.html(), "bar<hr><hr>");
+
+  R.set('baz');
+  lst.another();
+  Meteor.flush();
+  test.equal(div.html(), "baz<hr><hr><hr>");
+
+  div.kill();
+  Meteor.flush();
+});