The files attached at https://bugs.kde.org/show_bug.cgi?id=307080 do not work for me with okular 20.12.3 (debian testing, KDE frameworks 5.78.0, Qt 5.15.2, libpng 1.6.37-3) Both attached cbz display the okular icon and output on stderr: libpng warning: zTXt: CRC error libpng error: PNG unsigned integer out of range QImage::scaled: Image is a null image libpng warning: zTXt: CRC error libpng error: PNG unsigned integer out of range QImage::scaled: Image is a null image libpng warning: zTXt: CRC error libpng error: PNG unsigned integer out of range QImage::scaled: Image is a null image libpng warning: zTXt: CRC error libpng error: PNG unsigned integer out of range QImage::scaled: Image is a null image (the same thing for both files, on files without buggy images nothing is printed) Opening the images directly without the cbz wrapper works fine.
A possibly relevant merge request was started @ https://invent.kde.org/graphics/okular/-/merge_requests/424
Git commit f31152d389fc5ce348f836c749d66e71a66f3949 by Albert Astals Cid. Committed on 12/05/2021 at 20:52. Pushed by aacid into branch 'release/21.04'. Fix loading some png files inside zip comicbook files M +9 -1 generators/comicbook/document.cpp https://invent.kde.org/graphics/okular/commit/f31152d389fc5ce348f836c749d66e71a66f3949