reverted chunky_png version pushed that by mistake and patched a bug that was causing callbacks to register twice

Gemfile.lock

@@ -1,8 +1,8 @@
 PATH
   remote: .
   specs:
-    compass (0.11.beta.3.0fdf606)
-      chunky_png (~> 1.1.0)
+    compass (0.11.beta.3.6ff877c)
+      chunky_png (~> 0.12)
       sass (>= 3.1.0.alpha.249)
 
 GEM
@@ -38,7 +38,7 @@ GEM
     addressable (2.2.4)
     arel (2.0.9)
     builder (2.1.2)
-    chunky_png (1.1.0)
+    chunky_png (0.12.0)
     compass-validator (3.0.0)
     css_parser (1.0.1)
     cucumber (0.9.4)

compass.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |gemspec|
   gemspec.summary = %q{A Real Stylesheet Framework}
 
   gemspec.add_dependency 'sass', '>= 3.1.0.alpha.249'
-  gemspec.add_dependency 'chunky_png', '~> 1.1.0'
+  gemspec.add_dependency 'chunky_png', '~> 0.12'
 
   gemspec.files = %w(README.markdown LICENSE.markdown VERSION.yml Rakefile)
   gemspec.files += Dir.glob("bin/*")

lib/compass/configuration/helpers.rb

@@ -65,12 +65,15 @@ module Compass
             Sass::Plugin.add_template_location sass_dir, css_dir
           end
         end
+        unless defined?(CallbacksSetup)
           Sass::Plugin.on_updating_stylesheet do |sass_file, css_file|
             Compass.configuration.run_callback(:stylesheet_saved, css_file)
           end
           Sass::Plugin.on_compilation_error do |e, filename, css|
             Compass.configuration.run_callback(:stylesheet_error, filename, e.message)
           end
+          const_set('CallbacksSetup', true)
+        end
       end
 
       def sass_engine_options

spec/sprites_spec.rb

@@ -1,5 +1,4 @@
 require File.expand_path(File.dirname(__FILE__) + '/spec_helper')
-require "compass/sprites"
 require 'digest/md5'
 
 describe Compass::Sprites do
@@ -441,4 +440,31 @@ describe Compass::Sprites do
     CSS
   end
   
+  it "should calculate corret sprite demsions when givin spacing via issue#253" do
+    css = render <<-SCSS
+      $squares-spacing: 10px;
+      @import "squares/*.png";
+      .foo {
+        @include sprite-background-position($squares-sprites, "twenty-by-twenty");
+      }
+      .bar {
+        @include sprite-background-position($squares-sprites, "ten-by-ten");
+      }
+    SCSS
+    image_size('squares-*.png').should == [20, 40]
+    css.should == <<-CSS
+      .squares-sprite {
+        background: url('/squares-e3c68372d9.png') no-repeat;
+      }
+      
+      .foo {
+        background-position: 0 -20px;
+      }
+      
+      .bar {
+        background-position: 0 0;
+      }
+    CSS
+  end
+
 end