Normalize settings.COMPRESS_ROOT in setting mangling instead in CSS default filter.

compressor/filters/css_default.py

@@ -12,7 +12,7 @@ URL_PATTERN = re.compile(r'url\(([^\)]+)\)')
 
 class CssAbsoluteFilter(FilterBase):
     def input(self, filename=None, basename=None, **kwargs):
-        self.root = os.path.normcase(os.path.abspath(settings.COMPRESS_ROOT))
+        self.root = settings.COMPRESS_ROOT
         if filename is not None:
             filename = os.path.normcase(os.path.abspath(filename))
         if (not (filename and filename.startswith(self.root)) and

compressor/settings.py

@@ -1,3 +1,4 @@
+import os
 from django import VERSION as DJANGO_VERSION
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
@@ -66,7 +67,7 @@ class CompressorSettings(AppSettings):
         if not value:
             raise ImproperlyConfigured(
                 "The COMPRESS_ROOT setting must be set.")
-        return value
+        return os.path.normcase(os.path.abspath(value))
 
     def configure_url(self, value):
         # Uses Django 1.3's STATIC_URL by default or falls back to MEDIA_URL