Don't lookup resource for path if the path is absolute. Fixes middlem…

…an#1195

middleman-core/features/helpers_link_to.feature

@@ -5,6 +5,24 @@ Feature: link_to helper
     When I go to "/link_to_erb.html"
     Then I should see "erb <s>with html tags</s>"
 
+  Scenario: link_to works with absolute URLs (where the relative part matches a local path)
+    Given a fixture app "link-to-app"
+    And a file named "config.rb" with:
+    """
+    set :relative_links, true
+    """
+    And a file named "source/test.html.erb" with:
+    """
+    Hello
+    """
+    And a file named "source/link_to_absolute.html.erb" with:
+    """
+    <%= link_to "test", "http://google.com/test.html" %>
+    """
+    And the Server is running at "link-to-app"
+    When I go to "/link_to_absolute.html"
+    Then I should see '<a href="http://google.com/test.html">test</a>'
+
   Scenario: link_to works with blocks (slim)
     Given the Server is running at "link-to-app"
     When I go to "/link_to_slim.html"

middleman-core/lib/middleman-core/util.rb

@@ -169,14 +169,14 @@ def url_for(app, path_or_resource, options={})
         if path_or_resource.is_a?(::Middleman::Sitemap::Resource)
           resource = path_or_resource
           resource_url = url
-        elsif this_resource && uri.path
+        elsif this_resource && uri.path && !uri.host
           # Handle relative urls
           url_path = Pathname(uri.path)
           current_source_dir = Pathname('/' + this_resource.path).dirname
           url_path = current_source_dir.join(url_path) if url_path.relative?
           resource = app.sitemap.find_resource_by_path(url_path.to_s)
           resource_url = resource.url if resource
-        elsif options[:find_resource] && uri.path
+        elsif options[:find_resource] && uri.path && !uri.host
           resource = app.sitemap.find_resource_by_path(uri.path)
           resource_url = resource.url if resource
         end