From 4ea69c2d5ca9c436d22271745fa18ce8361d4983 Mon Sep 17 00:00:00 2001
From: Steven Orvell <sorvell@google.com>
Date: Fri, 21 Aug 2015 17:08:33 -0700
Subject: [PATCH] Fixes #2334: when composing nodes in shady dom, check if a
 node is where we expect it to be before removing it from its distributed
 position. We do this because the node may have been moved by Polymer.dom in a
 way that triggered distribution of its previous location. The node is already
 where it needs to be so removing it from its parent when it's no longer
 distributed is destructive.

---
 src/mini/shady.html                |  8 ++-
 test/unit/polymer-dom-content.html | 78 ++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+), 1 deletion(-)

diff --git a/src/mini/shady.html b/src/mini/shady.html
index cfa5f938cc..0caa80eab4 100644
--- a/src/mini/shady.html
+++ b/src/mini/shady.html
@@ -300,7 +300,13 @@
         // process removals
         for (var i=0, d=0, s; (i<splices.length) && (s=splices[i]); i++) {
           for (var j=0, n; (j < s.removed.length) && (n=s.removed[j]); j++) {
-            remove(n);
+            // check if the node is still where we expect it is before trying
+            // to remove it; this can happen if Polymer.dom moves a node and 
+            // then schedules its previous host for distribution resulting in
+            // the node being removed here.
+            if (getComposedParent(n) === container) {
+              remove(n);
+            }
             composed.splice(s.index + d, 1);
           }
           d -= s.addedCount;
diff --git a/test/unit/polymer-dom-content.html b/test/unit/polymer-dom-content.html
index c10224a0d6..9ff18071b9 100644
--- a/test/unit/polymer-dom-content.html
+++ b/test/unit/polymer-dom-content.html
@@ -29,6 +29,17 @@
   </script>
 </dom-module>
 
+<dom-module id="x-dist-simple">
+  <template>
+    <content id="content"></content>
+  </template>
+  <script>
+  HTMLImports.whenReady(function() {
+    Polymer({is: 'x-dist-simple'});
+  });
+  </script>
+</dom-module>
+
 <dom-module id="x-dist-inside-deep-tree">
   <template>
     x-dist-inside-deep-tree
@@ -1171,6 +1182,73 @@
       document.body.removeChild(h1);
     });
 
+    test('moving children between distributing host with shallow insertion and fragment', function() {
+      var h1 = document.createElement('x-dist-simple');
+      var h2 = document.createDocumentFragment();;
+      document.body.appendChild(h1);
+      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.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h2).childNodes.length, 0);
+      Polymer.dom(h2).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h2).childNodes.length, 1);
+      assert.equal(Polymer.dom(h2).firstElementChild, d);
+      assert.equal(Polymer.dom(h1).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h1.$.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.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h2).childNodes.length, 0);
+      Polymer.dom(h2).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h2).childNodes.length, 1);
+      assert.equal(Polymer.dom(h2).firstElementChild, d);
+      assert.equal(Polymer.dom(h1).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes().length, 0);
+      document.body.removeChild(h1);
+    });
+
+    test('moving children between distributing host with shallow insertion and fragment (parsed child)', function() {
+      var div = document.createElement('div');
+      div.innerHTML = '<x-dist-simple><div></div></x-dist-simple>';
+      var h1 = div.firstChild;
+      var h2 = document.createDocumentFragment();;
+      document.body.appendChild(h1);
+      Polymer.dom.flush();
+      var d = Polymer.dom(h1).firstElementChild;
+      assert.equal(d.localName, 'div');
+      assert.equal(Polymer.dom(h1).childNodes.length, 1);
+      assert.equal(Polymer.dom(h1).firstElementChild, d);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h2).childNodes.length, 0);
+      Polymer.dom(h2).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h2).childNodes.length, 1);
+      assert.equal(Polymer.dom(h2).firstElementChild, d);
+      assert.equal(Polymer.dom(h1).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h1.$.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.$.content).getDistributedNodes(), [d]);
+      assert.equal(Polymer.dom(h2).childNodes.length, 0);
+      Polymer.dom(h2).appendChild(d);
+      Polymer.dom.flush();
+      assert.equal(Polymer.dom(h2).childNodes.length, 1);
+      assert.equal(Polymer.dom(h2).firstElementChild, d);
+      assert.equal(Polymer.dom(h1).childNodes.length, 0);
+      assert.deepEqual(Polymer.dom(h1.$.content).getDistributedNodes().length, 0);
+      document.body.removeChild(h1);
+    });
+
     test('moving an element containing a dom-repeat that distributes items', function() {
       var x1 = document.createElement('x-repeat');
       var div = document.createElement('div');