only handle hashes that start with a '/'

- createHashHistory now only handles hashes that start with a '/' on
  history-change
- on startup, a '/' is still prepended if missing

Change-Id: Ibed14c8acde9c1ea022508c29be8b04df175d466

CHANGES.md

@@ -1,5 +1,7 @@
 ## [HEAD]
 
+- `createHashHistory` now only handles hashes that start with a '/' as only those urls may be created by the history
+
 - Disable browser history on Chrome iOS ([#146])
 - Add ES2015 module build ([#152])
 

modules/__tests__/HashHistory-test.js

@@ -15,8 +15,8 @@ import describeGo from './describeGo'
 
 describe('hash history', function () {
   beforeEach(function () {
-    if (window.location.hash !== '')
-      window.location.hash = ''
+    if (window.location.hash !== '/')
+      window.location.hash = '/'
   })
 
   describeInitialLocation(createHashHistory)

modules/createHashHistory.js

@@ -71,8 +71,8 @@ function createHashHistory(options={}) {
 
   function startHashChangeListener({ transitionTo }) {
     function hashChangeListener() {
-      if (!ensureSlash())
-        return // Always make sure hashes are preceeded with a /.
+      if (!isAbsolutePath(getHashPath()))
+        return // Only handle hashes which are could be created by the history.
 
       transitionTo(
         getCurrentLocation()