Scrollback buffer corruption when resizing and font: misplaced newline #7033
Description
Describe the bug
A scrollback line is broken (line-broken) several characters too soon, somewhere in the process of:
- Increasing font size, causing some lines to scroll off the top
- Restoring font size
To Reproduce
kitty --config NONE -o allow_remote_control=y bash -c '
sleep 1
cols=$(tput cols)
rows=$(tput lines)
for (( y = 0 ; y < $rows; y++ )); do
printf "["
for (( x = 2; x < $cols; x++ )); do
if (( y % 2 == 0 )); then
printf "="
else
printf "."
fi
done
printf "]"
done
sleep 0.5
kitty @ set-font-size +1
kitty @ set-font-size -- -1
kitty @ scroll-window start
read
'
(I got the idea to write this from the repro script in #2619 👍🏼 )
You may not need the leading sleep 1 in the script. I seemed to need it to allow Sway time enough to get the new window into its final size.
I experimented with the rows setting in the script and found interesting things. For instance:
# The errantly inserted line break occurs one line before it does normally
rows=$(( $(tput lines) - 1 ))
# No bug happens -- I guess there are not enough lines for output to scroll
# off the top of the viewport?
rows=$(( $(tput lines) / 2 ))
P.S. Thank you for kitty! I've been using it for several years, and I ❤️ it! :)
Screenshots
Environment details
Press Ctrl+Shift+F6 [...]
This didn't work for me; I just got the message below. I'm on a fairly crusty Arch system that's been installed for about four years, so maybe something is misconfigured due to too much experimentation over the years. I can reproduce and post debug info from my work machine, too, though, if that's helpful!
Failed to launch child: usr/bin/less
With error: No such file or directory
Press Enter or Esc to exit