fix($browser): don’t use history api when only the hash changes

IE10/11 have the following problem: When changing the url hash
via `history.pushState()` and then reverting the hash via direct
changes to `location.href` (or via a link) does not fire a
`hashchange` nor `popstate` event.

This commit changes the default behavior as follows:
Uses `location.href`/`location.replace` if the new url differs from
the previous url only in the hash fragment or the browser
does not support history API.
Use `history.pushState`/ `history.replaceState` otherwise.

Fixes #9143
Closes #9406

Author: tbosch

Diff for: src/ng/browser.js

@@ -153,8 +153,13 @@ function Browser(window, document, $log, $sniffer) {
     // setter
     if (url) {
       if (lastBrowserUrl == url) return;
+      var sameBase = lastBrowserUrl && stripHash(lastBrowserUrl) === stripHash(url);
       lastBrowserUrl = url;
-      if ($sniffer.history) {
+      // Don't use history API if only the hash changed
+      // due to a bug in IE10/IE11 which leads
+      // to not firing a `hashchange` nor `popstate` event
+      // in some cases (see #9143).
+      if (!sameBase && $sniffer.history) {
         if (replace) history.replaceState(null, '', url);
         else {
           history.pushState(null, '', url);

Diff for: src/ng/location.js

@@ -682,6 +682,9 @@ function $LocationProvider(){
 
       if (absHref && !elm.attr('target') && !event.isDefaultPrevented()) {
         if ($location.$$parseLinkUrl(absHref, relHref)) {
+          // We do a preventDefault for all urls that are part of the angular application,
+          // in html5mode and also without, so that we are able to abort navigation without
+          // getting double entries in the location history.
           event.preventDefault();
           // update location manually
           if ($location.absUrl() != $browser.url()) {

Diff for: test/ng/browserSpecs.js

@@ -440,6 +440,17 @@ describe('browser', function() {
       expect(locationReplace).not.toHaveBeenCalled();
     });
 
+    it('should set location.href and not use pushState when the url only changed in the hash fragment to please IE10/11', function() {
+      sniffer.history = true;
+      browser.url('http://server/#123');
+
+      expect(fakeWindow.location.href).toEqual('http://server/#123');
+
+      expect(pushState).not.toHaveBeenCalled();
+      expect(replaceState).not.toHaveBeenCalled();
+      expect(locationReplace).not.toHaveBeenCalled();
+    });
+
     it('should use location.replace when history.replaceState not available', function() {
       sniffer.history = false;
       browser.url('http://new.org', true);
@@ -451,6 +462,17 @@ describe('browser', function() {
       expect(fakeWindow.location.href).toEqual('http://server/');
     });
 
+    it('should use location.replace and not use replaceState when the url only changed in the hash fragment to please IE10/11', function() {
+      sniffer.history = true;
+      browser.url('http://server/#123', true);
+
+      expect(locationReplace).toHaveBeenCalledWith('http://server/#123');
+
+      expect(pushState).not.toHaveBeenCalled();
+      expect(replaceState).not.toHaveBeenCalled();
+      expect(fakeWindow.location.href).toEqual('http://server/');
+    });
+
     it('should return $browser to allow chaining', function() {
       expect(browser.url('http://any.com')).toBe(browser);
     });