Piping and redirection are broken in Windows

[veltza]

I noticed that the latest Chafa version 1.16.0 no longer works with lf. It seems that the issue is caused by broken piping and redirection in that version.

For example, if you try to run these commands in PowerShell, they will freeze the shell:

Chafa.exe -f symbols .\ff8a8ad6.jpg | Out-File -FilePath output.txt

Chafa.exe -f symbols .\ff8a8ad6.jpg > output.txt

The issue also occurs in MSYS2 with Bash and Zsh.

Edit: Shortened the title

[hpjansson]

Thanks for testing and reporting, as always. It's likely related to the new I/O code. I'll try to get a 1.16.1 release out quickly with a fix for this and any other regressions that are found in the meantime.

[hpjansson]

It looks good in my tests now. @veltza, can you confirm?

There's one more Windows pipe-related issue I keep running into: When piping a file to chafa's stdin in PowerShell, the data is always corrupted, and I haven't found an -Encoding setting that fixes it. Is there something I can do to make it better behaved?

[veltza]

I'm sorry, but I don't have the tools to compile Chafa on Windows.

[hpjansson]

Ok, no problem. The reason testing is kind of spotty is that Windows is a difficult platform to target coming from Linux. I'm using MXE to cross-compile it myself, so there's no "make check" to catch Windows-only bugs.

[veltza]

I have now tested the new version 1.16.1 and it works well with piping, redirection and lf. But I ran into a strange issue when I tried to run Chafa in PowerShell. It closes the shell after the command:

> chafa --version
Chafa version 1.16.1

Loaders:  GIF JPEG PNG QOI SVG TIFF WebP XWD
Features: mmx sse4.1 popcnt avx2
Applying: mmx sse4.1 popcnt avx2

Copyright (C) 2018-2025 Hans Petter Jansson et al.
Incl. libnsgif copyright (C) 2004 Richard Wilson, copyright (C) 2008 Sean Fox
Incl. LodePNG copyright (C) 2005-2018 Lode Vandevenne
Incl. QOI decoder copyright (C) 2021 Dominic Szablewski

This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

>
[process exited with code 2 (0x00000002)]
You can now close this terminal with Ctrl+D, or press Enter to restart.

It only happens in Windows Terminal (v1.22.11141.0), but not in Alacritty and Wezterm. Interestingly, command prompt and MSYS2 (zsh) do not have this issue either.

Can you reproduce this?

[hpjansson]

I have now tested the new version 1.16.1 and it works well with piping, redirection and lf. But I ran into a strange issue when I tried to run Chafa in PowerShell. It closes the shell after the command:
[...]
It only happens in Windows Terminal (v1.22.11141.0), but not in Alacritty and Wezterm. Interestingly, command prompt and MSYS2 (zsh) do not have this issue either.

Can you reproduce this?

Yes. It happens with Chafa 1.16.0+ in combination with Windows Terminal 1.22.11141.0, but not with Windows Terminal Preview 1.23.10732.0. Maybe it's hitting a bug in Windows Terminal.

[veltza]

Yes. It happens with Chafa 1.16.0+ in combination with Windows Terminal 1.22.11141.0, but not with Windows Terminal Preview 1.23.10732.0. Maybe it's hitting a bug in Windows Terminal.

Good to know that it is a known issue and will likely be fixed in the next WT version. I mainly use Chafa with lf, so it won't affect me much. Thanks for all your hard work!

[hpjansson]

I've tried to disable the MinGW wildcard expansion code and manually joining our threads on exit. Unfortunately neither had any impact on the Windows Terminal issue. Hope their preview version gets a mainline release soon.

[j4james]

@hpjansson If you know what the issue was that was fixed, it might be worth asking them to consider backporting it in a 1.22 servicing release. Because it might be quite a while before the next stable version increment.