--- diffviewer/forms.py	(revision 616)
+++ diffviewer/forms.py	(working copy)
@@ -33,6 +33,7 @@
 
         # Check that we can actually get all these files.
         tool = repository.get_scmtool()
+        tool.parse_extra_info_headers(file["content"])
 
         if tool.get_diffs_use_absolute_paths():
             basedir = ''
--- scmtools/core.py	(revision 616)
+++ scmtools/core.py	(working copy)
@@ -72,6 +72,9 @@
     def parse_diff_revision(self, file_str, revision_str):
         raise NotImplementedError
 
+    def parse_extra_info_headers(self, file):
+        return False
+
     def get_diffs_use_absolute_paths(self):
         return False