Revert "Merge pull request #4803 from lucascaton/master"

This reverts commit bb842e8, reversing
changes made to 40c287c.
This was causing issues in one of our apps we just upgraded.
ActionController::RoutingError: No route matches [GET]
"/images/favicon.ico"
favicon_link_tag now returns '/images/favicon.ico' and in 3.2 returned
'/favicon.ico'
Browsers by default look for favicon.ico in the root directory

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/lib/action_view/helpers/asset_tag_helper.rb

actionpack/CHANGELOG.md

@@ -1019,8 +1019,6 @@
     not submitted with the form. This is a behavior change, previously the hidden
     tag had a value of the disabled checkbox. *Tadas Tamosauskas*
 
-*   `favicon_link_tag` helper will now use the favicon in app/assets by default. *Lucas Caton*
-
 *   `ActionView::Helpers::TextHelper#highlight` now defaults to the
     HTML5 `mark` element. *Brian Cardarella*
 

actionpack/lib/action_view/helpers/asset_tag_helper.rb

@@ -152,7 +152,7 @@ def auto_discovery_link_tag(type = :rss, url_options = {}, tag_options = {})
       # * <tt>:type</tt>  - Override the auto-generated mime type, defaults to 'image/vnd.microsoft.icon'
       #
       #   favicon_link_tag '/myicon.ico'
-      #   # => <link href="/assets/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />
+      #   # => <link href="/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />
       #
       # Mobile Safari looks for a different <link> tag, pointing to an image that
       # will be used if you add the page to the home screen of an iPod Touch, iPhone, or iPad.
@@ -161,7 +161,7 @@ def auto_discovery_link_tag(type = :rss, url_options = {}, tag_options = {})
       #   favicon_link_tag '/mb-icon.png', rel: 'apple-touch-icon', type: 'image/png'
       #   # => <link href="/assets/mb-icon.png" rel="apple-touch-icon" type="image/png" />
       #
-      def favicon_link_tag(source='favicon.ico', options={})
+      def favicon_link_tag(source='/favicon.ico', options={})
         tag('link', {
           :rel  => 'shortcut icon',
           :type => 'image/vnd.microsoft.icon',

actionpack/test/template/asset_tag_helper_test.rb

@@ -200,7 +200,7 @@ def url_for(*args)
   }
 
   FaviconLinkToTag = {
-    %(favicon_link_tag) => %(<link href="/images/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />),
+    %(favicon_link_tag) => %(<link href="/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />),
     %(favicon_link_tag 'favicon.ico') => %(<link href="/images/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />),
     %(favicon_link_tag 'favicon.ico', :rel => 'foo') => %(<link href="/images/favicon.ico" rel="foo" type="image/vnd.microsoft.icon" />),
     %(favicon_link_tag 'favicon.ico', :rel => 'foo', :type => 'bar') => %(<link href="/images/favicon.ico" rel="foo" type="bar" />),