From 89f124b5771ef1688f691cba4b7ec68446975a1c Mon Sep 17 00:00:00 2001
From: Eric Kelly <heroiceric@gmail.com>
Date: Wed, 20 Jan 2016 22:10:46 -0500
Subject: [PATCH] [BUGFIX beta] Fix `BuildUrlMixin.urlPrefix` regression when
 host is "/"
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Fixes https://github.com/emberjs/data/issues/4105

I couldn't think of a better name for the test ¯\_(ツ)_/¯
---
 addon/-private/adapters/build-url-mixin.js    |  6 +++++-
 .../adapter/build-url-mixin-test.js           | 20 +++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/addon/-private/adapters/build-url-mixin.js b/addon/-private/adapters/build-url-mixin.js
index f67cc558e3d..07ab6d79e68 100644
--- a/addon/-private/adapters/build-url-mixin.js
+++ b/addon/-private/adapters/build-url-mixin.js
@@ -218,9 +218,13 @@ export default Ember.Mixin.create({
     @return {String} urlPrefix
   */
   urlPrefix(path, parentURL) {
-    var host = get(this, 'host') || '';
+    var host = get(this, 'host');
     var namespace = get(this, 'namespace');
 
+    if (!host || host === '/') {
+      host = '';
+    }
+
     if (path) {
       // Protocol relative url
       if (/^\/\//.test(path) || /http(s)?:\/\//.test(path)) {
diff --git a/tests/integration/adapter/build-url-mixin-test.js b/tests/integration/adapter/build-url-mixin-test.js
index a1c53ce9737..7f6bf98e67c 100644
--- a/tests/integration/adapter/build-url-mixin-test.js
+++ b/tests/integration/adapter/build-url-mixin-test.js
@@ -128,6 +128,26 @@ test('buildURL - with absolute paths in links and protocol relative host', funct
   }));
 });
 
+test('buildURL - with absolute paths in links and host is /', function(assert) {
+  run(function() {
+    adapter.setProperties({
+      host: '/',
+      namespace: 'api/v1'
+    });
+  });
+  Post.reopen({ comments: DS.hasMany('comment', { async: true }) });
+  Comment.reopen({ post: DS.belongsTo('post', { async: false }) });
+
+  ajaxResponse({ posts: [{ id: 1, links: { comments: '/api/v1/posts/1/comments' } }] });
+
+  run(store, 'findRecord', 'post', 1).then(assert.wait(function(post) {
+    ajaxResponse({ comments: [{ id: 1 }] });
+    return post.get('comments');
+  })).then(assert.wait(function (comments) {
+    assert.equal(passedUrl, '/api/v1/posts/1/comments', 'host stripped out properly');
+  }));
+});
+
 test('buildURL - with full URLs in links', function(assert) {
   adapter.setProperties({
     host: 'http://example.com',