From bd7aa63c14b8f8e894bd65d14d889a07623560eb Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 25 Jul 2022 18:45:54 +0530
Subject: [PATCH] Container: handle internal hrefs that result in ValueError
 when try to resolve them on windows

---
 src/calibre/ebooks/oeb/polish/container.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/calibre/ebooks/oeb/polish/container.py b/src/calibre/ebooks/oeb/polish/container.py
index 589eae83c1..4bb53e8bd1 100644
--- a/src/calibre/ebooks/oeb/polish/container.py
+++ b/src/calibre/ebooks/oeb/polish/container.py
@@ -118,7 +118,10 @@ def href_to_name(href, root, base=None):
         # assume all such paths are invalid/absolute paths.
         return None
     fullpath = os.path.join(base, *href.split('/'))
-    return unicodedata.normalize('NFC', abspath_to_name(fullpath, root))
+    try:
+        return unicodedata.normalize('NFC', abspath_to_name(fullpath, root))
+    except ValueError:
+        return None
 
 
 class ContainerBase:  # {{{