more from glasser review

packages/minimongo/minimongo.js

@@ -373,6 +373,7 @@ LocalCollection.Cursor.prototype._depend = function (changers) {
                options[fnName] = notifyChange;
            });
 
+    // observeChanges will stop() when this computation is invalidated
     self.observeChanges(options);
   }
 };

packages/minimongo/minimongo_tests.js

@@ -1774,7 +1774,9 @@ Tinytest.add("minimongo - reactive stop", function (test) {
   // observe callbacks don't wait for flush, they are inline.
   coll.insert({_id: 'F'});
   test.equal(x, "FEDCBA");
+  test.equal(y, "FEDCBA");
   Deps.flush();
   coll.insert({_id: 'G'});
   test.equal(x, "FEDCBA");
+  test.equal(y, "FEDCBA");
 });