From c3aa3b241f8c32c2b6d8f5aec30b8b2432ca0b83 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 23 Apr 2015 08:22:05 +0530
Subject: [PATCH] When sorting filenames in comics treat the file extension as
 a secondary sort key.

---
 src/calibre/libunzip.py    | 8 ++++++--
 src/calibre/utils/unrar.py | 4 ++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/calibre/libunzip.py b/src/calibre/libunzip.py
index 172d1ce512..bad66f35bb 100644
--- a/src/calibre/libunzip.py
+++ b/src/calibre/libunzip.py
@@ -5,6 +5,7 @@ __docformat__ = 'restructuredtext en'
 
 import re
 from calibre.utils import zipfile
+from calibre.utils.icu import numeric_sort_key
 
 def update(pathtozip, patterns, filepaths, names, compression=zipfile.ZIP_DEFLATED, verbose=True):
     '''
@@ -43,12 +44,15 @@ def extract(filename, dir):
     zf = zipfile.ZipFile(filename)
     zf.extractall(dir)
 
+def sort_key(filename):
+    bn, ext = filename.rpartition('.')[::2]
+    return (numeric_sort_key(bn), numeric_sort_key(ext))
+
 def extract_member(filename, match=re.compile(r'\.(jpg|jpeg|gif|png)\s*$', re.I), sort_alphabetically=False):
     zf = zipfile.ZipFile(filename)
     names = list(zf.namelist())
     if sort_alphabetically:
-        from calibre.utils.icu import numeric_sort_key
-        names.sort(key=numeric_sort_key)
+        names.sort(key=sort_key)
     for name in names:
         if match.search(name):
             return name, zf.read(name)
diff --git a/src/calibre/utils/unrar.py b/src/calibre/utils/unrar.py
index 96f0d2820b..c3940ad68f 100644
--- a/src/calibre/utils/unrar.py
+++ b/src/calibre/utils/unrar.py
@@ -185,9 +185,9 @@ def extract_member(stream, match=re.compile(r'\.(jpg|jpeg|gif|png)\s*$', re.I),
             return h['filename'], et.getvalue()
 
 def extract_first_alphabetically(stream):
-    from calibre.utils.icu import numeric_sort_key
+    from calibre.libunzip import sort_key
     names_ = sorted([x for x in names(stream) if os.path.splitext(x)[1][1:].lower() in
-            {'png', 'jpg', 'jpeg', 'gif'}], key=numeric_sort_key)
+            {'png', 'jpg', 'jpeg', 'gif', 'webp'}], key=sort_key)
     return extract_member(stream, name=names_[0], match=None)
 
 # Test normal RAR file {{{