[Bug] Broken rendering with auto-detected Kitty protocol on KDE Konsole — Sixel works

[gwpl]

AI Assistant:

Description

mdfried auto-detects Kitty graphics protocol when running in KDE Konsole, but rendering is broken — especially when scrolling. Forcing Sixel protocol via --debug-override-protocol-type sixel resolves the issue and renders correctly.

Konsole has full Sixel support but only partial Kitty graphics protocol support, which likely explains the mismatch.

Steps to Reproduce

1. Open KDE Konsole
2. Run mdfried some-file-with-images.md
3. mdfried detects Kitty protocol
4. Scroll through the document — rendering artifacts / broken output

Expected Behavior

Either:

• mdfried should detect that Konsole's Kitty graphics protocol support is incomplete and fall back to Sixel, or
• Rendering with the Kitty protocol should work correctly in Konsole

Workaround

mdfried --debug-override-protocol-type sixel file.md

This produces correct rendering and scrolling behavior.

Environment

• mdfried: 0.18.2 (Arch Linux extra/mdfried)
• Konsole: 25.08.2
• OS: Arch Linux

[benjajaja]

@gwpl you need to use Sixel with uppercase, otherwise it just falls through to Halfblocks. So the workaround is not correct, you have been seeing the halfblocks/chafa ASCII-art rendering that does not glitch. If you used Sixel, you will see that it also glitches but differently: sixel graphics are never cleared from overwriting text. This is noted in ratatui-image.

Bottomline: will block konsole from using kitty and sixel in ratatui-image (here: ratatui/ratatui-image#145), so it will just use halfblocks/chafa. Also see the konsole bug report, which is marked as resolved: https://bugs.kde.org/show_bug.cgi?id=456354

[benjajaja]

actually will close this once I release with the konsole fix in.