From 6af9997c7cfd47c4b6ebb05021172fa1cf3a4a64 Mon Sep 17 00:00:00 2001 From: Kovid Goyal Date: Sun, 27 May 2018 08:29:22 +0530 Subject: [PATCH] EPUB Output: Fix an error causing conversion to fail when outputting to EPUB 3 and the input document has no preexisting nav. Fixes #1773533 [epub to epub conversion failed due to Python problem](https://bugs.launchpad.net/calibre/+bug/1773533) --- src/calibre/ebooks/conversion/plugins/epub_output.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/calibre/ebooks/conversion/plugins/epub_output.py b/src/calibre/ebooks/conversion/plugins/epub_output.py index 3741d3c9a4..ae164f753d 100644 --- a/src/calibre/ebooks/conversion/plugins/epub_output.py +++ b/src/calibre/ebooks/conversion/plugins/epub_output.py @@ -298,7 +298,8 @@ class EPUBOutput(OutputFormatPlugin): from calibre.ebooks.oeb.polish.upgrade import epub_2_to_3 existing_nav = getattr(self.opts, 'epub3_nav_parsed', None) nav_href = getattr(self.opts, 'epub3_nav_href', None) - epub_2_to_3(container, self.log.info, previous_nav=(nav_href, existing_nav)) + previous_nav = (existing_nav, nav_href) if existing_nav and nav_href else None + epub_2_to_3(container, self.log.info, previous_nav=previous_nav) fix_conversion_titlepage_links_in_nav(container) container.commit() os.remove(f.name)