Checklist

• I have read through the manual page (man fzf)
• I have searched through the existing issues
• For bug reports, I have checked if the bug is reproducible in the latest version of fzf

Output of fzf --version

0.73.1 (Homebrew)

OS

• Linux
• macOS
• Windows
• Etc.

Shell

• bash
• zsh
• fish

Problem / Steps to reproduce

One day, I encountered jittering when scrolling up/down on my macOS trackpad in fzf. I realized it was because the horizontal scroll component is factored in, so if you scroll 45° up and right or 45° down and left, the scroll counteracts itself! I propose that horizontal mouse wheel events should not count as vertical scrolling.

Reproducing

1. Use a terminal that supports horizontal scrolling (e.g., Ghostty, Alacritty, Kitty, etc.).
2. Scroll horizontally in fzf.
3. Scrolling left should scroll upwards. Scrolling right should scroll downwards.

The Fix

I believe the issue has to do with lines 908-915 of light.go. The logic for SGR mouse wheel events is as follows. Is this intended?

I made a branch with the following changes:

I just made horizontal scrolling a no-op. In the future, we can support proper horizontal scrolling (#4824).