[ Reason ]
Fix Debian bug 1143484
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1143484

[ Impact ]
Failed to convert ePub file with obfuscated fonts

[ Tests ]
Build time unit test was successful.

[ Risks ]
I don't have ePub file with obfuscated fonts.
So I can't test specific file conversions.

[ Checklist ]
  [x] *all* changes are documented in the d/changelog
  [x] I reviewed all changes and I approve them
  [x] attach debdiff against the package in (old)stable
  [x] the issue is verified as fixed in unstable

[ Changes ]
Add fixup to CVE-2026-25636 fix that in 8.5.0+ds-1+deb13u2.

[ Other info ]
debdiff is too big because it includes file rename.
I also add minimized diff file that drops renamed files.

You can examine from online:
https://github.com/debian-
calibre/calibre/compare/debian/8.5.0+ds-1+deb13u3...debian/trixie

Hello,
https://idpf.github.io/epub3-samples/30/samples.html .
And add autopkgtest for this issue.

You can examine from online:
https://github.com/debian-calibre/calibre/compare/debian/8.5.0+ds-1+deb13u3...debian/trixie

Hello,

I was added CVE-2026-53511 fix for deb13u4 update.

You can examine from online:
https://github.com/debian-calibre/calibre/compare/debian/8.5.0+ds-1+deb13u3...debian/trixie