fix($location): fix and test html5Mode url-parsing algorithm for legacy browsers

This CL fixes problems and adds test cases for changes from angular#6421. Changes
include fixing the algorithm for preprocessing href attribute values, as
well as supporting xlink:href attributes. Credit for the original URL
parsing algorithm still goes to @richardcrichardc.

Good work, champ!

Author: caitp

src/ng/location.js

@@ -653,33 +653,34 @@ function $LocationProvider(){
       }
 
       // Make relative links work in HTML5 mode for legacy browsers (or at least IE8 & 9)
-      // The href should be a regular url e.g. /link/somewhere or link/somewhere or ../somewhere or somewhere#anchor or http://example.com/somewhere
+      // The href should be a regular url e.g. /link/somewhere or link/somewhere or ../somewhere or
+      // somewhere#anchor or http://example.com/somewhere
       if (LocationMode === LocationHashbangInHtml5Url) {
-        // get the actual href attribute - see http://msdn.microsoft.com/en-us/library/ie/dd347148(v=vs.85).aspx
-        // TODO check browser is in standards mode
-        var href = elm[0].getAttribute('href');
+        // get the actual href attribute - see
+        // http://msdn.microsoft.com/en-us/library/ie/dd347148(v=vs.85).aspx
+        var href = elm.attr('href') || elm.attr('xlink:href');
 
-        if (href.indexOf('://' == -1)) {         // Ignore absolute URLs
+        if (href.indexOf('://') < 0) {         // Ignore absolute URLs
+          var prefix = '#' + hashPrefix;
           if (href[0] == '/') {
             // absolute path - replace old path
-            absHref = serverBase(absHref) + href;
+            absHref = appBase + prefix + href;
           } else if (href[0] == '#') {
             // local anchor
-            absHref = serverBase(absHref) + $location.path() + href;
+            absHref = appBase + prefix + ($location.path() || '/') + href;
           } else {
             // relative path - join with current path
             var stack = $location.path().split("/"),
               parts = href.split("/");
-            stack.pop(); // remove top file
             for (var i=0; i<parts.length; i++) {
               if (parts[i] == ".")
                 continue;
               else if (parts[i] == "..")
                 stack.pop();
-              else
+              else if (parts[i].length)
                 stack.push(parts[i]);
             }
-            absHref = serverBase(absHref) + stack.join("/");
+            absHref = appBase + prefix + stack.join('/');
           }
         }
       }

test/ng/locationSpec.js

@@ -779,15 +779,22 @@ describe('$location', function() {
 
     var root, link, originalBrowser, lastEventPreventDefault;
 
-    function configureService(linkHref, html5Mode, supportHist, attrs, content) {
+    function configureService(linkHref, html5Mode, supportHist, relLink, attrs, content) {
+      if (typeof relLink !== "boolean") {
+        content = attrs;
+        attrs = relLink;
+        relLink = false;
+      }
       module(function($provide, $locationProvider) {
         attrs = attrs ? ' ' + attrs + ' ' : '';
 
         // fake the base behavior
-        if (linkHref[0] == '/') {
-          linkHref = 'http://host.com' + linkHref;
-        } else if(!linkHref.match(/:\/\//)) {
-          linkHref = 'http://host.com/base/' + linkHref;
+        if (!relLink) {
+          if (linkHref[0] == '/') {
+            linkHref = 'http://host.com' + linkHref;
+          } else if(!linkHref.match(/:\/\//)) {
+            linkHref = 'http://host.com/base/' + linkHref;
+          }
         }
 
         link = jqLite('<a href="' + linkHref + '"' + attrs + '>' + content + '</a>')[0];
@@ -1067,6 +1074,51 @@ describe('$location', function() {
     });
 
 
+    it('should rewrite relative links relative to current path when history disabled', function() {
+      configureService('link', true, false, true);
+      inject(
+        initBrowser(),
+        initLocation(),
+        function($browser, $location) {
+          $location.path('/some');
+          browserTrigger(link, 'click');
+          expectRewriteTo($browser, 'http://host.com/base/index.html#!/some/link');
+        }
+      );
+    });
+
+
+    it('should replace current path when link begins with "/" and history disabled', function() {
+      configureService('/link', true, false, true);
+      inject(
+        initBrowser(),
+        initLocation(),
+        function($browser, $location) {
+          $location.path('/some');
+          browserTrigger(link, 'click');
+          expectRewriteTo($browser, 'http://host.com/base/index.html#!/link');
+        }
+      );
+    });
+
+
+    it('should replace current hash fragment when link begins with "#" history disabled', function() {
+      configureService('#link', true, false, true);
+      inject(
+        initBrowser(),
+        initLocation(),
+        function($browser, $location) {
+          // Initialize browser URL
+          $location.path('/some');
+          $location.hash('foo');
+          browserTrigger(link, 'click');
+          expect($location.hash()).toBe('link');
+          expectRewriteTo($browser, 'http://host.com/base/index.html#!/some#link');
+        }
+      );
+    });
+
+
     // don't run next tests on IE<9, as browserTrigger does not simulate pressed keys
     if (!(msie < 9)) {