From a031f072146548ccf2d8c75944d0f1d62b6b6878 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 5 Apr 2021 22:09:46 +0530
Subject: [PATCH] CHM Input: Fix a regression in calibre 5.0 that broke opening
 of some files that dont specify a character encoding. Fixes #1922503 [E-book
 viewer: error opening a *.chm
 file](https://bugs.launchpad.net/calibre/+bug/1922503)

py3 compat
---
 src/calibre/ebooks/chm/reader.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/calibre/ebooks/chm/reader.py b/src/calibre/ebooks/chm/reader.py
index 1139777787..e4f9ecf86e 100644
--- a/src/calibre/ebooks/chm/reader.py
+++ b/src/calibre/ebooks/chm/reader.py
@@ -77,6 +77,8 @@ class CHMReader(CHMFile):
                 ans = lcid[0]
         if ans:
             try:
+                if isinstance(ans, bytes):
+                    ans = ans.decode('ascii')
                 codecs.lookup(ans)
             except Exception:
                 ans = None