Is this a escape-seq bug?

[Rudxain]

mathiasbynens/dotfiles#930 ; same thing happens with my dotfiles.

It seems the simplest repro is to append \nSOMETHING to PS1 and notice that whatever styling is applied before the line-feed doesn't actually apply after it

[TomJo2000]

A screenshot of the issue would be helpful because I don't think I'm able to replicate it, but I may be looking for the wrong thing.

[Rudxain]

Expected (example) prompt:

~/downloads
$

Actual prompt:

~/downloads
$

I've only tested with bold, but I expect the same happens with coloring

[TomJo2000]

Can't replicate the issue with the $PS1 from the repo you linked to.

What is the actual PS1 value for the prompt you are using?

[Rudxain]

I found a minimal repro. On a clean install of Termux 0.119.0-beta.3 (ARM) run this cmd:

PS1='\[\e[1m\]\w\n$ \[\e[0m\]'

The entire prompt will be bold, until we resize the terminal (pinch-to-zoom).

The weird thing is that, when it's my dotfiles' prompt, the 2nd line is never bold (no need to resize). Here's a copy of the file, because the commit-hashes are unstable:

#!/bin/sh
#shellcheck disable=SC2155

case "$TERM" in
	xterm-color|*-256color) color_support=y;;
	*) color_support=n;;
esac

last_exit() {
	local e=$?
	[ $e -ne 0 ] && \
		printf "${1:-}%02x${2:-} " $e
	return $e
}

if [ $color_support = y ]; then
	# all bold, red exit-code
	PS1="\n\[\e[1m\]\$(last_exit \"\[\e[31m\]\" \"\[\e[0m\]\[\e[1m\]\")"
else
	PS1="\n\$(last_exit)"
fi
PS1="$PS1\w"

if command -v git >/dev/null; then
	git_b_name() {
		git rev-parse --is-inside-work-tree >/dev/null 2>&1 || return
		# "//" unambiguously delimits paths and branches,
		# because it should never be a substr of either
		echo " // $(\
			git symbolic-ref --quiet --short HEAD 2>/dev/null || \
			git describe --all --exact-match HEAD 2>/dev/null || \
			git rev-parse --short HEAD 2>/dev/null || \
			echo '(?)' \
		)"
	}
	PS1="$PS1\$(git_b_name)"
fi

# common suffix
PS1="$PS1\nΔ "
[ $color_support = y ] && PS1="$PS1\[\e[0m\]"
unset color_support

I "fixed" it on my side by replacing PS1="$PS1\nΔ " by PS1="$PS1\n\[\e[1m\]Δ " (re-apply bold styling)

[sylirre]

@Rudxain Open a bug report ticket with full explanation (video preferred) about the issue.

It seems to happen because Termux "rebuilds" lines while pinch-zooming and escape sequence take effect only before \n.

[Rudxain]

#4658