Add url_converter method to storage.py

openedx/core/djangoapps/theming/storage.py

@@ -179,6 +179,71 @@ class ThemeCachedFilesMixin(CachedFilesMixin):
         processed_asset_name = self._processed_asset_name(name)
         return super(ThemeCachedFilesMixin, self)._url(hashed_name_func, processed_asset_name, force, hashed_files)
 
+    def url_converter(self, name, hashed_files, template=None):
+        """
+        This is an override of url_converter from CachedFilesMixin.
+        It changes one line near the end of the method (see the NOTE) in order
+        to return absolute urls instead of relative urls.  This behavior is
+        necessary for theme overrides, as we get 404 on assets with relative
+        urls on a themed site.
+        """
+        if template is None:
+            template = self.default_template
+
+        def converter(matchobj):
+            """
+            Convert the matched URL to a normalized and hashed URL.
+            This requires figuring out which files the matched URL resolves
+            to and calling the url() method of the storage.
+            """
+            matched, url = matchobj.groups()
+
+            # Ignore absolute/protocol-relative and data-uri URLs.
+            if re.match(r'^[a-z]+:', url):
+                return matched
+
+            # Ignore absolute URLs that don't point to a static file (dynamic
+            # CSS / JS?). Note that STATIC_URL cannot be empty.
+            if url.startswith('/') and not url.startswith(settings.STATIC_URL):
+                return matched
+
+            # Strip off the fragment so a path-like fragment won't interfere.
+            url_path, fragment = urldefrag(url)
+
+            if url_path.startswith('/'):
+                # Otherwise the condition above would have returned prematurely.
+                assert url_path.startswith(settings.STATIC_URL)
+                target_name = url_path[len(settings.STATIC_URL):]
+            else:
+                # We're using the posixpath module to mix paths and URLs conveniently.
+                source_name = name if os.sep == '/' else name.replace(os.sep, '/')
+                target_name = posixpath.join(posixpath.dirname(source_name), url_path)
+
+            # Determine the hashed name of the target file with the storage backend.
+            hashed_url = self._url(
+                self._stored_name, unquote(target_name),
+                force=True, hashed_files=hashed_files,
+            )
+
+            # NOTE:
+            # The line below was commented out so that absolute urls are used instead of relative urls to make themed
+            # assets work correctly.
+            #
+            # The line is commented and not removed to make future django upgrade easier and show exactly what is
+            # changed in this method override
+            #
+            #transformed_url = '/'.join(url_path.split('/')[:-1] + hashed_url.split('/')[-1:])
+            transformed_url = hashed_url  # This line was added.
+
+            # Restore the fragment that was stripped off earlier.
+            if fragment:
+                transformed_url += ('?#' if '?#' in url else '#') + fragment
+
+            # Return the hashed version to the file
+            return template % unquote(transformed_url)
+
+        return converter
+
 
 class ThemePipelineMixin(PipelineMixin):
     """