Avoid non-bubbling event gotchas with binding.

src/lib/bind/bind.html

@@ -23,7 +23,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
     _addAnnotatedListener: function(model, index, property, path) {
       // <node>.on.<property>-changed: <path> = e.detail.value
       //
-      var changedFn = '\tthis.' + path + ' = e.detail.value;';
+      var changedFn = '\t\tthis.' + path + ' = e.detail.value;';
       if (path.indexOf('.') > 0) {
         // TODO(kschaaf): dirty check avoids null references when the object has gone away
         changedFn = 
@@ -32,12 +32,15 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
           '\t\tthis.notifyPath(\'' + path + '\', e.detail.value)\n' +
           '\t}';
       }
-      changedFn = 'if (e.detail.path) {\n' +
-        '\tvar path = this._fixPath(\'' + path + '\', \'' + 
+      changedFn = 
+        'if (!e.path || e.path[0] == e.target) {\n' +
+        '\tif (e.detail.path) {\n' +
+        '\t\tvar path = this._fixPath(\'' + path + '\', \'' + 
           property + '\', e.detail.path);\n' + 
-        '\tthis.notifyPath(path, e.detail.value);\n' +
-        '} else {\n' +
+        '\t\tthis.notifyPath(path, e.detail.value);\n' +
+        '\t} else {\n' +
         changedFn + '\n' +
+        '\t}\n' + 
         '}';
       //
       model._bindListeners.push({

test/unit/bind-elements.html

@@ -143,3 +143,47 @@
     }
   });
 </script>
+
+<script>
+  Polymer({
+    is: 'x-notifies1',
+    properties: {
+      notifies: {
+        notify: true
+      }
+    }
+  });
+</script>
+
+<dom-module id="x-notifies2">
+  <template>
+    <x-notifies1 id="notifies1"></x-notifies1>
+  </template>
+</dom-module>
+<script>
+  Polymer({
+    is: 'x-notifies2',
+    properties: {
+      notifies: {
+        notify: true
+      }
+    }
+  });
+</script>
+
+<dom-module id="x-notifies3">
+  <template>
+    <x-notifies2 id="notifies2" notifies="{{shouldNotChange}}"></x-notifies2>
+  </template>
+</dom-module>
+<script>
+  Polymer({
+    is: 'x-notifies3',
+    properties: {
+      shouldNotChange: {
+        observer: 'shouldNotChangeChanged'
+      }
+    },
+    shouldNotChangeChanged: function() { }
+  });
+</script>

test/unit/bind.html

@@ -593,6 +593,29 @@ suite('binding to attribute', function() {
 
 });
 
+suite('avoid non-bubbling event gotchas', function() {
+
+  var el;
+
+  beforeEach(function() {
+    el = document.createElement('x-notifies3');
+    document.body.appendChild(el);
+  });
+
+  afterEach(function() {
+    document.body.removeChild(el);
+  });
+
+  test('avoid non-bubbling event gotchas', function() {
+    el.shouldNotChangeChanged = function(e) {
+      assert(false, 'parent notifies should not have changed');
+    };
+    el.$.notifies2.$.notifies1.notifies = 42;
+  });
+
+});
+
+
 </script>