URL:
<https://savannah.gnu.org/bugs/?62125>
Summary: Error on read (some) 4-bit PNG images
Project: GNU GRUB
Submitted by: patl1729
Submitted on: Mon 28 Feb 2022 05:35:26 PM UTC
Category: Terminal
Severity: Major
Priority: 5 - Normal
Item Group: None
Status: None
Privacy: Public
Assigned to: None
Originator Name:
Originator Email:
Open/Closed: Open
Release:
Release: 2.02
Discussion Lock: Any
Reproducibility: None
Planned Release: None
_______________________________________________________
Details:
The attached PNG file is valid. It was generated by "pnmtopng"; it loads in
every viewer I have tried; and it passes "pngcheck".
But when I try to load it from GRUB (UEFI boot) using "background_image", I
get this error:
error: ../../grub-core/video/readers/png.c:595 invalid filter value
Note that this image's depth is 4 bits (with a palette):
$ pngcheck -v logo-save.png | head -3
File: logo-save.png (594 bytes)
chunk IHDR at offset 0x0000c, length 13
640 x 480 image, 4-bit palette, non-interlaced
When I modify this image to add more colors, making the depth 8 bits, GRUB can
load the modified image without any trouble.
Possibly related, the validation check at png.c line 286:
https://git.savannah.gnu.org/cgit/grub.git/tree/grub-core/video/readers/png.c?h=grub-2.02#n286
...specifically allows a 4-bit image depth. (Separate bug: The error message
on line 290 does not match the check.)
I believe others have encountered the same bug; see e.g.
https://bugs.mageia.org/show_bug.cgi?id=28225
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Mon 28 Feb 2022 05:35:26 PM UTC Name: logo.png Size: 594B By:
patl1729
<http://savannah.gnu.org/bugs/download.php?file_id=52942>
_______________________________________________________
Reply to this item at:
<https://savannah.gnu.org/bugs/?62125>
_______________________________________________
Message sent via Savannah
https://savannah.gnu.org/
