From 671d5cec4be1f0f03384567e651d4246c7132b1c Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 31 Aug 2024 15:38:08 +0530
Subject: [PATCH] Handle invalid xmnlns:= and xmlns=

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

diff --git a/src/calibre/ebooks/oeb/reader.py b/src/calibre/ebooks/oeb/reader.py
index 005d63159f..0fe46ca7e4 100644
--- a/src/calibre/ebooks/oeb/reader.py
+++ b/src/calibre/ebooks/oeb/reader.py
@@ -106,6 +106,8 @@ class OEBReader:
                 elem.tag = OPF(barename(elem.tag))
         nsmap.update(OPF2_NSMAP)
         attrib = dict(opf.attrib)
+        if xmlns := attrib.pop('xmlns:'):
+            attrib['xmlns'] = xmlns
         nroot = etree.Element(OPF('package'),
             nsmap={None: OPF2_NS}, attrib=attrib)
         metadata = etree.SubElement(nroot, OPF('metadata'), nsmap=nsmap)