Fix timing issue with multiple stamps (#42)

Author: bedeoverend

iron-lazy-pages-behavior.html

@@ -88,12 +88,13 @@
     }
     this._setLoading(true);
     event.detail.item._loadAndShow(function(cb) {
+      var protectedCb = this.selectedItem === event.detail.item ? cb : function(){};
       this._setLoading(false);
       if (this._lastSelected) {
         this._callback = cb;
-        this._hide(this._lastSelected, cb)
+        this._hide(this._lastSelected, protectedCb)
       } else {
-        cb();
+        protectedCb();
       }
       if (this.selectedAttribute) {
         event.detail.item._toggleAttribute(this.selectedAttribute, true);

test/basic-test.html

@@ -295,6 +295,21 @@
             pages.select('foo');
             assertStamped('Foo');
           });
+
+          test('does not stamp late load if no longer selected', function() {
+            var firstSuccessCallback;
+
+            fakeImport(0, 'foo.html');
+            pages.select('foo');
+            firstSuccessCallback = callbackSuccess;
+
+            fakeImport(1, 'bar.html');
+            pages.select('bar');
+            callbackSuccess();
+            firstSuccessCallback();
+
+            assertStamped('Bar');
+          });
         }
      });
     </script>