From 54c880fb2b2e0f9d3454a4dbbaeae904708b271f Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 23 Apr 2015 08:24:15 +0530
Subject: [PATCH] ...

---
 src/calibre/libunzip.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/calibre/libunzip.py b/src/calibre/libunzip.py
index bad66f35bb..8599b372cb 100644
--- a/src/calibre/libunzip.py
+++ b/src/calibre/libunzip.py
@@ -46,6 +46,8 @@ def extract(filename, dir):
 
 def sort_key(filename):
     bn, ext = filename.rpartition('.')[::2]
+    if not bn and ext:
+        bn, ext = ext, bn
     return (numeric_sort_key(bn), numeric_sort_key(ext))
 
 def extract_member(filename, match=re.compile(r'\.(jpg|jpeg|gif|png)\s*$', re.I), sort_alphabetically=False):