fix($location): make legacy browsers behave like modern ones in html5…

…Mode

Previously, LocationHashbangInHtml5Url, which is used when html5Mode is enabled
in browsers which do not support the history API (IE8/9), would behave very
inconsistently WRT relative URLs always being resolved relative to the app root
url.

This fix enables these legacy browsers to behave like history enabled browsers,
by processing href attributes in order to resolve urls correctly.

Closes angular#6162
Closes angular#6421
Closes angular#6899
Closes angular#6832
Closes angular#6834

src/ng/location.js

@@ -268,6 +268,16 @@ function LocationHashbangInHtml5Url(appBase, hashPrefix) {
       return appBaseNoFile;
     }
   };
+
+  this.$$compose = function() {
+    var search = toKeyValue(this.$$search),
+        hash = this.$$hash ? '#' + encodeUriSegment(this.$$hash) : '';
+
+    this.$$url = encodePath(this.$$path) + (search ? '?' + search : '') + hash;
+    // include hashPrefix in $$absUrl when $$url is empty so IE8 & 9 do not reload page because of removal of '#'
+    this.$$absUrl = appBase + hashPrefix + this.$$url;
+  };
+
 }
 
 
@@ -642,6 +652,38 @@ function $LocationProvider(){
         absHref = urlResolve(absHref.animVal).href;
       }
 
+      // 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
+      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');
+
+        if (href.indexOf('://' == -1)) {         // Ignore absolute URLs
+          if (href[0] == '/') {
+            // absolute path - replace old path
+            absHref = serverBase(absHref) + href;
+          } else if (href[0] == '#') {
+            // local anchor
+            absHref = serverBase(absHref) + $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
+                stack.push(parts[i]);
+            }
+            absHref = serverBase(absHref) + stack.join("/");
+          }
+        }
+      }
+
       var rewrittenUrl = $location.$$rewrite(absHref);
 
       if (absHref && !elm.attr('target') && rewrittenUrl && !event.isDefaultPrevented()) {