fix($location): allow navigating outside the original base URL

Previously, if you navigated outside of the current base URL angular
crashed with a `Cannot call method 'charAt' of undefined` error.

Closes angular#11302
Closes angular#4776

Author: tsuyoshizawa

src/ng/location.js

@@ -185,7 +185,7 @@ function LocationHashbangUrl(appBase, hashPrefix) {
     var withoutBaseUrl = beginsWith(appBase, url) || beginsWith(appBaseNoFile, url);
     var withoutHashUrl;
 
-    if (withoutBaseUrl.charAt(0) === '#') {
+    if (!isUndefined(withoutBaseUrl) && withoutBaseUrl.charAt(0) === '#') {
 
       // The rest of the url starts with a hash so we have
       // got either a hashbang path or a plain hash fragment
@@ -199,7 +199,15 @@ function LocationHashbangUrl(appBase, hashPrefix) {
       // There was no hashbang path nor hash fragment:
       // If we are in HTML5 mode we use what is left as the path;
       // Otherwise we ignore what is left
-      withoutHashUrl = this.$$html5 ? withoutBaseUrl : '';
+      if (this.$$html5) {
+        withoutHashUrl = withoutBaseUrl;
+      } else {
+        withoutHashUrl = '';
+        if (isUndefined(withoutBaseUrl)) {
+          appBase = url;
+          this.replace();
+        }
+      }
     }
 
     parseAppUrl(withoutHashUrl, this);

test/ng/locationSpec.js

@@ -2462,6 +2462,14 @@ describe('$location', function() {
     it('should throw on url(urlString, stateObject)', function() {
       expectThrowOnStateChange(locationUrl);
     });
+
+    it('should allow navigating outside the original base URL', function() {
+      locationUrl = new LocationHashbangUrl('http://server/pre/index.html', '#');
+
+      locationUrl.$$parse('http://server/next/index.html');
+      expect(locationUrl.url()).toBe('');
+      expect(locationUrl.absUrl()).toBe('http://server/next/index.html');
+    });
   });