Fixes #2253: refine logical tree check and populate parents of insert…

…ion points with logical info only if necessary.

Fixes #2283: when a node is removed, we need to potentially distribute not only its host but also its parent.

@@ -65,10 +65,10 @@
       // 3. node is <content> (host of container needs distribution)
       appendChild: function(node) {
         var handled;
-        // if a <content> is added, make sure it's parent has logical info.
-        this._ensureContentLogicalInfo(node);
         this._removeNodeFromHost(node, true);
         if (this._nodeIsInLogicalTree(this.node)) {
+          // if a <content> is added, make sure it's parent has logical info.
+          this._ensureContentLogicalInfo(node);
           this._addLogicalInfo(node, this.node);
           this._addNodeToHost(node);
           handled = this._maybeDistribute(node, this.node);
@@ -90,10 +90,10 @@
           return this.appendChild(node);
         }
         var handled;
-        // if a <content> is added, make sure it's parent has logical info.
-        this._ensureContentLogicalInfo(node);
         this._removeNodeFromHost(node, true);
         if (this._nodeIsInLogicalTree(this.node)) {
+          // if a <content> is added, make sure it's parent has logical info.
+          this._ensureContentLogicalInfo(node);
           var children = this.childNodes;
           var index = children.indexOf(ref_node);
           if (index < 0) {
@@ -242,11 +242,10 @@
         }
       },
 
-      // a node is in a shadyRoot, is a shadyRoot,
-      // or has a lightParent
+      // a node has logical info associated with it
       _nodeIsInLogicalTree: function(node) {
-        return Boolean((node._lightParent !== undefined) || node._isShadyRoot ||
-          node.shadyRoot);
+        return Boolean(node._lightParent !== undefined || 
+          node._lightChildren !== undefined);
       },
 
       _ensureContentLogicalInfo: function(node) {
@@ -270,11 +269,16 @@
       // NOTE: if `ensureComposedRemoval` is true then the node should be
       // removed from its composed parent.
       _removeNodeFromHost: function(node, ensureComposedRemoval) {
+        // note that it's possible for both the node's host and its parent 
+        // to require distribution... both cases are handled here.
         var hostNeedsDist;
         var root;
         var parent = node._lightParent;
         if (parent) {
+          // distribute node's parent iff needed
+          factory(node)._distributeParent();
           root = this._ownerShadyRootForNode(node);
+          // remove node from root and distribute it iff needed
           if (root) {
             root.host._elementRemove(node);
             hostNeedsDist = this._removeDistributedChildren(root, node);
@@ -938,7 +942,7 @@
     }
 
     function hasInsertionPoint(root) {
-      return Boolean(root._insertionPoints.length);
+      return Boolean(root && root._insertionPoints.length);
     }
 
     var p = Element.prototype;

@@ -20,7 +20,7 @@
 <dom-module id="x-dist">
   <template>
     x-dist
-    <div id="distWrapper"><content></content></div>
+    <div id="distWrapper"><content id="content"></content></div>
   </template>
   <script>
   HTMLImports.whenReady(function() {
@@ -832,6 +832,45 @@
       }
     });
 
+    test('moving children between distributing hosts', function() {
+      var h1 = document.createElement('x-dist');
+      var h2 = document.createElement('x-dist');
+      document.body.appendChild(h1);
+      document.body.appendChild(h2);
+      Polymer.dom.flush();
+      var d = document.createElement('div');
+      Polymer.dom(h1).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h1).childNodes.length, 1);
+      assert.equal(Polymer.dom(h1).firstElementChild, d);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h2).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h2.$.content).getDistributedNodes().length, 0);
+      Polymer.dom(h2).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h2).childNodes.length, 1);
+      assert.equal(Polymer.dom(h2).firstElementChild, d);
+      assert.deepEqual(Polymer.dom(h2.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h1).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes().length, 0);
+      Polymer.dom(h1).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h1).childNodes.length, 1);
+      assert.equal(Polymer.dom(h1).firstElementChild, d);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h2).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h2.$.content).getDistributedNodes().length, 0);
+      Polymer.dom(h2).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h2).childNodes.length, 1);
+      assert.equal(Polymer.dom(h2).firstElementChild, d);
+      assert.deepEqual(Polymer.dom(h2.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h1).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes().length, 0);
+      document.body.removeChild(h1);
+      document.body.removeChild(h2);
+    });
+
   });
 
   suite('multi-content mutations', function() {

@@ -424,6 +424,24 @@ suite('Polymer.dom', function() {
     assert.equal(Polymer.dom(rere.root).querySelectorAll('span').length, 0);
   });
 
+  test('mutations using fragments without logical dom', function() {
+    var d = document.createElement('div');
+    document.body.appendChild(d);
+    assert.equal(Polymer.dom(d).childNodes.length, 0);
+    var frag = document.createDocumentFragment();
+    var c = document.createElement('div');
+    frag.appendChild(c);
+    Polymer.dom(d).appendChild(frag);
+    assert.equal(Polymer.dom(d).childNodes.length, 1);
+    assert.equal(Polymer.dom(d).firstChild, c);
+    var c1 = document.createElement('div');
+    frag.appendChild(c1);
+    Polymer.dom(d).appendChild(frag);
+    assert.equal(Polymer.dom(d).childNodes.length, 2);
+    assert.equal(Polymer.dom(d).firstChild, c);
+    assert.equal(Polymer.dom(d).lastChild, c1);
+  });
+
   test('appendChild interacts with unmanaged parent tree', function() {
     var container = document.querySelector('#container');
     var echo = Polymer.dom(container).firstElementChild;