#2818 gnuplot-6.0.x - qt terminal error "IFFChunk::innerFromDevice: unkwnown chunk"

[Anonymous]

Since gnuplot-6.0.x, I got this error message "IFFChunk::innerFromDevice: unkwnown chunk". The error appears when I use 'qt' terminal but disappears if I use other terminal like 'wxt'.

How to reproduce the bug:

$ cat test.sh
#/bin/bash
gnuplot <<EOF
set terminal qt
plot sin(x)
pause mouse close
EOF

$ ./test.sh 
IFFChunk::innerFromDevice: unkwnown chunk "/* X"
IFFChunk::innerFromDevice: unkwnown chunk "/* X"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "/* X"
IFFChunk::innerFromDevice: unkwnown chunk "/* X"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"
IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"

gnuplot version:

$ gnuplot -V
gnuplot 6.0.3 patchlevel 3 (Gentoo revision r0)

platform:

$ kinfo
Operating System: Gentoo Linux 2.17
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.1.145-gentoo (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7 CPU         950  @ 3.07GHz
Memory: 36 GiB of RAM (35.3 GiB usable)
Graphics Processor: NVIDIA GeForce GTX 1650

[Ethan Merritt]

After a system upgrade I'm getting this message also. II think it comes from one of the KDE Qt6 plugin libraries. On my system this symbol is found in kimg_iff.so, which is provided by kimageformats-6.16.0.

Upstream fix may be this commit. I am not sure this actually fixes it; just sends the message via a different path.

https://invent.kde.org/frameworks/kimageformats/-/commit/083680eb7729f02eb5d086782f45c042309d0911

chunks.cpp - send info and warning messages to the iff logging category
For example:
`IFFChunk::innerFromDevice: unkwnown chunk "\x89PNG"`

becomes:
`kf.imageformats.plugins.iff: IFFChunk::innerFromDevice: unknown chunk "\x89PNG"`

bonus: we can filter out such messages if we want using QT_LOGGING_RULES

also note the spelling fix

[Ethan Merritt]

The change should be in kimageformats-6.18.0, if I am reading the repository notes correctly.

[Ethan Merritt]

I can confirm that kimageformats 6.16.0 gives the spurious error and 6.17.0 does not.