fix($location): always resolve relative links in html5mode to <base> url

BREAKING CHANGE (since 1.2.0 and 1.3.0-beta.1):

Angular now requires a `<base>` tag when html5 mode of `$location` is enabled. Reasoning:
Using html5 mode without a `<base href="...">` tag makes relative links for images, links, ...
relative to the current url if the browser supports
the history API. However, if the browser does not support the history API Angular falls back to using the `#`,
and then all links would be broken.

BREAKING CHANGE (since 1.2.17 and 1.3.0-beta.10):

In html5 mode without a `<base>` tag on older browser that don't support the history API
relative paths were adding up. E.g. clicking on `<a href="page1">` and then on `<a href="page2">`
would produce `$location.path()==='/page1/page2'. The code that introduced this behavior was removed
and Angular now also requires a `<base>` tag to be present when using html5 mode.

Closes angular#8172

Author: tbosch

src/ng/location.js

@@ -127,21 +127,32 @@ function LocationHtml5Url(appBase, basePrefix) {
     this.$$absUrl = appBaseNoFile + this.$$url.substr(1); // first char is always '/'
   };
 
-  this.$$rewrite = function(url) {
+  this.$$parseLinkUrl = function(url, relHref) {
+    if (relHref && relHref[0] === '#') {
+      // special case for links to hash fragments:
+      // keep the old url and only replace the hash fragment
+      this.hash(relHref.slice(1));
+      return true;
+    }
     var appUrl, prevAppUrl;
+    var rewrittenUrl;
 
     if ( (appUrl = beginsWith(appBase, url)) !== undefined ) {
       prevAppUrl = appUrl;
       if ( (appUrl = beginsWith(basePrefix, appUrl)) !== undefined ) {
-        return appBaseNoFile + (beginsWith('/', appUrl) || appUrl);
+        rewrittenUrl = appBaseNoFile + (beginsWith('/', appUrl) || appUrl);
       } else {
-        return appBase + prevAppUrl;
+        rewrittenUrl = appBase + prevAppUrl;
       }
     } else if ( (appUrl = beginsWith(appBaseNoFile, url)) !== undefined ) {
-      return appBaseNoFile + appUrl;
+      rewrittenUrl = appBaseNoFile + appUrl;
     } else if (appBaseNoFile == url + '/') {
-      return appBaseNoFile;
+      rewrittenUrl = appBaseNoFile;
+    }
+    if (rewrittenUrl) {
+      this.$$parse(rewrittenUrl);
     }
+    return !!rewrittenUrl;
   };
 }
 
@@ -231,10 +242,12 @@ function LocationHashbangUrl(appBase, hashPrefix) {
     this.$$absUrl = appBase + (this.$$url ? hashPrefix + this.$$url : '');
   };
 
-  this.$$rewrite = function(url) {
+  this.$$parseLinkUrl = function(url, relHref) {
     if(stripHash(appBase) == stripHash(url)) {
-      return url;
+      this.$$parse(url);
+      return true;
     }
+    return false;
   };
 }
 
@@ -254,16 +267,28 @@ function LocationHashbangInHtml5Url(appBase, hashPrefix) {
 
   var appBaseNoFile = stripFile(appBase);
 
-  this.$$rewrite = function(url) {
+  this.$$parseLinkUrl = function(url, relHref) {
+    if (relHref && relHref[0] === '#') {
+      // special case for links to hash fragments:
+      // keep the old url and only replace the hash fragment
+      this.hash(relHref.slice(1));
+      return true;
+    }
+
+    var rewrittenUrl;
     var appUrl;
 
     if ( appBase == stripHash(url) ) {
-      return url;
+      rewrittenUrl = url;
     } else if ( (appUrl = beginsWith(appBaseNoFile, url)) ) {
-      return appBase + hashPrefix + appUrl;
+      rewrittenUrl = appBase + hashPrefix + appUrl;
     } else if ( appBaseNoFile === url + '/') {
-      return appBaseNoFile;
+      rewrittenUrl = appBaseNoFile;
     }
+    if (rewrittenUrl) {
+      this.$$parse(rewrittenUrl);
+    }
+    return !!rewrittenUrl;
   };
 
   this.$$compose = function() {
@@ -626,14 +651,18 @@ function $LocationProvider(){
         appBase;
 
     if (html5Mode) {
+      if (!baseHref) {
+        throw $locationMinErr('nobase',
+          "$location in HTML5 mode requires a <base> tag to be present!");
+      }
       appBase = serverBase(initialUrl) + (baseHref || '/');
       LocationMode = $sniffer.history ? LocationHtml5Url : LocationHashbangInHtml5Url;
     } else {
       appBase = stripHash(initialUrl);
       LocationMode = LocationHashbangUrl;
     }
     $location = new LocationMode(appBase, '#' + hashPrefix);
-    $location.$$parse($location.$$rewrite(initialUrl));
+    $location.$$parseLinkUrl(initialUrl, initialUrl);
 
     var IGNORE_URI_REGEXP = /^\s*(javascript|mailto):/i;
 
@@ -652,6 +681,9 @@ function $LocationProvider(){
       }
 
       var absHref = elm.prop('href');
+      // get the actual href attribute - see
+      // http://msdn.microsoft.com/en-us/library/ie/dd347148(v=vs.85).aspx
+      var relHref = elm.attr('href') || elm.attr('xlink:href');
 
       if (isObject(absHref) && absHref.toString() === '[object SVGAnimatedString]') {
         // SVGAnimatedString.animVal should be identical to SVGAnimatedString.baseVal, unless during
@@ -662,50 +694,15 @@ function $LocationProvider(){
       // Ignore when url is started with javascript: or mailto:
       if (IGNORE_URI_REGEXP.test(absHref)) return;
 
-      // 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
-        var href = elm.attr('href') || elm.attr('xlink:href');
-
-        if (href && href.indexOf('://') < 0) {         // Ignore absolute URLs
-          var prefix = '#' + hashPrefix;
-          if (href[0] == '/') {
-            // absolute path - replace old path
-            absHref = appBase + prefix + href;
-          } else if (href[0] == '#') {
-            // local anchor
-            absHref = appBase + prefix + ($location.path() || '/') + href;
-          } else {
-            // relative path - join with current path
-            var stack = $location.path().split("/"),
-              parts = href.split("/");
-            if (stack.length === 2 && !stack[1]) stack.length = 1;
-            for (var i=0; i<parts.length; i++) {
-              if (parts[i] == ".")
-                continue;
-              else if (parts[i] == "..")
-                stack.pop();
-              else if (parts[i].length)
-                stack.push(parts[i]);
-            }
-            absHref = appBase + prefix + stack.join('/');
-          }
-        }
-      }
-
-      var rewrittenUrl = $location.$$rewrite(absHref);
-
-      if (absHref && !elm.attr('target') && rewrittenUrl && !event.isDefaultPrevented()) {
-        event.preventDefault();
-        if (rewrittenUrl != $browser.url()) {
+      if (absHref && !elm.attr('target') && !event.isDefaultPrevented()) {
+        if ($location.$$parseLinkUrl(absHref, relHref)) {
+          event.preventDefault();
           // update location manually
-          $location.$$parse(rewrittenUrl);
-          $rootScope.$apply();
-          // hack to work around FF6 bug 684208 when scenario runner clicks on links
-          window.angular['ff-684208-preventDefault'] = true;
+          if ($location.absUrl() != $browser.url()) {
+            $rootScope.$apply();
+            // hack to work around FF6 bug 684208 when scenario runner clicks on links
+            window.angular['ff-684208-preventDefault'] = true;
+          }
         }
       }
     });

test/ng/anchorScrollSpec.js

@@ -110,6 +110,10 @@ describe('$anchorScroll', function() {
       return function($provide, $locationProvider) {
         $provide.value('$sniffer', {history: config.historyApi});
         $locationProvider.html5Mode(config.html5Mode);
+        $provide.decorator('$browser', function($delegate) {
+          $delegate.$$baseHref = '/';
+          return $delegate;
+        });
       };
     }