From fba95956de38355ab50d2235969ea8e0b94ae868 Mon Sep 17 00:00:00 2001
From: Benedikt McMullin <benedikt@mcmullin.de>
Date: Mon, 2 Jan 2023 21:21:43 +0100
Subject: [PATCH] epub: Skip invalid dc:identifier

---
 cps/epub.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cps/epub.py b/cps/epub.py
index 00ce907b..a807a2e6 100644
--- a/cps/epub.py
+++ b/cps/epub.py
@@ -102,7 +102,10 @@ def get_epub_info(tmp_file_path, original_file_name, original_file_extension):
 
     identifiers = []
     for node in p.xpath('dc:identifier', namespaces=ns):
-        identifier_name = node.attrib.values()[-1]
+        try:
+            identifier_name = node.attrib.values()[-1]
+        except IndexError:
+            continue
         identifier_value = node.text
         if identifier_name in ('uuid', 'calibre') or identifier_value is None:
             continue