[Rpm-metadata] [PATCH] Fix handling of symlinks pointing to a directory. BZ 969754

[Zdenek Pavlas]

> 2) process each symlink only once.  This breaks directory loops.
> Since we may have processed the target dir already, we process
> it at most twice.

Maybe we should not try to detect loops, but ANY means of processing
the same directory twice.. and err out instead:

--- a/createrepo/__init__.py
+++ b/createrepo/__init__.py
@@ -304,8 +304,15 @@ class MetaDataGenerator:
         recurse dirs. Returns a list object"""
 
         extlen = len(ext)
+        seen = set()
 
         def extension_visitor(filelist, dirname, names):
+            st = os.stat(dirname)
+            key = st.st_dev, st.st_ino
+            if key in seen:
+                msg = _('Directory \'%s\' listed more than once')
+                raise MDError, msg % dirname[len(startdir):]
+            seen.add(key)
             for fn in names:
                 fn = os.path.join(dirname, fn)
                 if os.path.isdir(fn):