Fixed that AssetTagHelper#image_tag and others using compute_public_path should not modify the incoming source argument (closes #5102) [eule@space.ch]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5003 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Fixed that AssetTagHelper#image_tag and others using compute_public_path should not modify the incoming source argument (closes #5102) [eule@space.ch]
+
 * Deprecated the auto-appending of .png to AssetTagHelper#image_tag calls that doesn't have an extension [DHH] 
 
 * Added locals hash to partials, which makes for convenient access of some times available/some times not variables #5491 [wbruce@gmail.com]. Example:

actionpack/lib/action_view/helpers/asset_tag_helper.rb

@@ -158,6 +158,7 @@ module ActionView
       
       private
         def compute_public_path(source, dir, ext)
+          source = source.dup
           source  = "/#{dir}/#{source}" unless source.first == "/" || source.include?(":")
           source << ".#{ext}" unless source.split("/").last.include?(".")
           source << '?' + rails_asset_id(source) if defined?(RAILS_ROOT) && %r{^[-a-z]+://} !~ source

actionpack/test/template/asset_tag_helper_test.rb

@@ -140,6 +140,15 @@ class AssetTagHelperTest < Test::Unit::TestCase
     ENV["RAILS_ASSET_ID"] = "4500"
     assert_equal %(<img alt="Rails" src="/images/rails.png?4500" />), image_tag("rails.png")
   end
+
+  def test_url_dup_image_tag
+    Object.send(:const_set, :RAILS_ROOT, File.dirname(__FILE__) + "/../fixtures/")
+    img_url = '/images/rails.png'
+    url_copy = img_url.dup
+    image_tag(img_url)
+    
+    assert_equal url_copy, img_url
+  end
 end
 
 class AssetTagHelperNonVhostTest < Test::Unit::TestCase