Fix d3#2722 - case-sensitivity of selection.append.

If the implicit namespace of the created element matches that of the document
element, the document’s createElement should be used instead of createElementNS.
This way, in documents for which createElement is case-insensitive—most notably
HTML documents—selection.append is likewise case-insensitive.

component.json

@@ -10,7 +10,7 @@
     "animation",
     "canvas"
   ],
-  "version": "3.5.13",
+  "version": "3.5.14",
   "main": "d3.js",
   "scripts": [
     "d3.js"

d3.js

@@ -1,6 +1,6 @@
 !function() {
   var d3 = {
-    version: "3.5.13"
+    version: "3.5.14"
   };
   var d3_arraySlice = [].slice, d3_array = function(list) {
     return d3_arraySlice.call(list);
@@ -805,7 +805,7 @@
   function d3_selection_creator(name) {
     function create() {
       var document = this.ownerDocument, namespace = this.namespaceURI;
-      return namespace ? document.createElementNS(namespace, name) : document.createElement(name);
+      return namespace && namespace !== document.documentElement.namespaceURI ? document.createElementNS(namespace, name) : document.createElement(name);
     }
     function createNS() {
       return this.ownerDocument.createElementNS(name.space, name.local);

package.js

@@ -3,7 +3,7 @@
 Package.describe({
   name: "d3js:d3", // http://atmospherejs.com/d3js/d3
   summary: "D3 (official): A JavaScript visualization library for HTML and SVG.",
-  version: "3.5.13",
+  version: "3.5.14",
   git: "https://github.com/mbostock/d3.git"
 });
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "d3",
-  "version": "3.5.13",
+  "version": "3.5.14",
   "description": "A JavaScript visualization library for HTML and SVG.",
   "keywords": [
     "dom",

src/selection/append.js

@@ -13,7 +13,7 @@ function d3_selection_creator(name) {
   function create() {
     var document = this.ownerDocument,
         namespace = this.namespaceURI;
-    return namespace
+    return namespace && namespace !== document.documentElement.namespaceURI
         ? document.createElementNS(namespace, name)
         : document.createElement(name);
   }

src/start.js

@@ -1,2 +1,2 @@
 !function(){
-  var d3 = {version: "3.5.13"}; // semver
+  var d3 = {version: "3.5.14"}; // semver

test/selection/append-test.js

@@ -41,6 +41,37 @@ suite.addBatch({
       "inherits namespace from parent node": function(body) {
         var g = body.append("svg:svg").append("g");
         assert.equal(g[0][0].namespaceURI, "http://www.w3.org/2000/svg");
+      },
+      "uses createElement when the implicit namespace matches the document": function(body) {
+        var document = body.node().ownerDocument, createElement = document.createElement, pass = 0;
+        document.createElement = function() { ++pass; return createElement.apply(this, arguments); };
+        try {
+          body.append("p");
+        } finally {
+          document.createElement = createElement;
+        }
+        assert.equal(pass, 1);
+      },
+      "uses createElementNS when the implicit namespace does not match the document": function(body) {
+        var document = body.node().ownerDocument, createElementNS = document.createElementNS, pass = 0;
+        document.createElementNS = function() { ++pass; return createElementNS.apply(this, arguments); };
+        try {
+          body.append("svg").append("g");
+        } finally {
+          document.createElementNS = createElementNS;
+        }
+        assert.equal(pass, 2);
+      },
+      "uses createElementNS when given an explicit namespace": function(body) {
+        var document = body.node().ownerDocument, createElementNS = document.createElementNS, pass = 0;
+        document.createElementNS = function() { ++pass; return createElementNS.apply(this, arguments); };
+        try {
+          body.append("svg:svg");
+          body.append("xhtml:p");
+        } finally {
+          document.createElementNS = createElementNS;
+        }
+        assert.equal(pass, 2);
       }
     }
   }