Use Addressable to improve inline url detection and rewriting. Only rewrite relative paths. Closes #1499

middleman-core/features/asset_host.feature

@@ -1,17 +1,4 @@
 Feature: Alternate between multiple asset hosts
-  In order to speed up page loading
-  
-  Scenario: Set single host globally
-    Given a fixture app "asset-host-app"
-    And a file named "config.rb" with:
-      """
-      activate :asset_host, host: "http://assets1.example.com"
-      """
-    And the Server is running
-    When I go to "/asset_host.html"
-    Then I should see "http://assets1"
-    When I go to "/stylesheets/asset_host.css"
-    Then I should see "http://assets1"
 
   Scenario: Set single host with inline-option
     Given a fixture app "asset-host-app"
@@ -21,6 +8,7 @@ Feature: Alternate between multiple asset hosts
       """
     And the Server is running
     When I go to "/asset_host.html"
+    Then I should see 'src="https://code.jquery.com/jquery-2.1.3.min.js"'
     Then I should see content matching %r{http://assets1.example.com/}
     Then I should not see content matching %r{http://assets1.example.com//}
     When I go to "/stylesheets/asset_host.css"
@@ -37,6 +25,7 @@ Feature: Alternate between multiple asset hosts
       """
     And the Server is running
     When I go to "/asset_host.html"
+    Then I should see 'src="https://code.jquery.com/jquery-2.1.3.min.js"'
     Then I should see content matching %r{http://assets1.example.com/}
     Then I should not see content matching %r{http://assets1.example.com//}
     When I go to "/stylesheets/asset_host.css"

middleman-core/fixtures/asset-host-app/source/asset_host.html.erb

@@ -1,3 +1,5 @@
+<script src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
+
 <%= image_tag "blank0.gif" %>
 <%= image_tag "blank1.gif" %>
 <%= image_tag "blank2.gif" %>

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

@@ -15,6 +15,7 @@ require 'rack/mime'
 require 'middleman-core/contracts'
 
 # For URI templating
+require 'addressable/uri'
 require 'addressable/template'
 require 'active_support/inflector'
 require 'active_support/inflector/transliterate'
@@ -323,11 +324,17 @@ module Middleman
         opening_character = $1
         asset_path = $2
 
-        if result = yield(asset_path)
+        begin
+          uri = ::Addressable::URI.parse(asset_path)
+
+          if uri.relative? && result = yield(asset_path)
             "#{opening_character}#{result}"
           else
             match
           end
+        rescue
+          match
+        end
       end
     end