Only set those compass configuration options that have been explicitl…

…y set by the user.

Closes GH-21.

lib/compass-rails.rb

@@ -177,8 +177,18 @@ def initialize!(config = nil)
 
     def configure_rails!(app)
       return unless app.config.respond_to?(:sass)
-      app.config.compass.to_sass_engine_options.each do |key, value|
-        app.config.sass.send(:"#{key}=", value)
+      sass_config = app.config.sass
+      compass_config = app.config.compass
+
+      sass_config.load_paths.concat(compass_config.sass_load_paths)
+
+      { :output_style => :style,
+        :line_comments => :line_comments,
+        :cache => :cache,
+        :disable_warnings => :quiet,
+        :preferred_syntax => :preferred_syntax
+      }.each do |compass_option, sass_option|
+        set_maybe sass_config, compass_config, sass_option, compass_option
       end
     end
 
@@ -198,6 +208,16 @@ def asset_pipeline_enabled?
     rails_config.respond_to?(:assets) && rails_config.assets.try(:enabled)
   end
 
+  private
+
+    # sets the sass config value only if the corresponding compass-based setting
+    # has been explicitly set by the user.
+    def set_maybe(sass_config, compass_config, sass_option, compass_option)
+      if compass_value = compass_config.send(:"#{compass_option}_without_default")
+        sass_config.send(:"#{sass_option}=", compass_value)
+      end
+    end
+
 end
 
 Compass::AppIntegration.register(:rails, "::CompassRails")