patch 9.0.2140: [security]: use-after-free in win-enter Commit: https://github.com/vim/vim/commit/eec0c2b3a4cfab93dd8d4adaa60638d47a2bbc8a Author: Christian Brabandt <cb@256bit.org> Date: Tue Nov 28 22:03:48 2023 +0100 patch 9.0.2140: [security]: use-after-free in win-enter Problem: [security]: use-after-free in win-enter Solution: validate window pointer before calling win_enter() win_goto() may stop visual mode, if it is active. However, this may in turn trigger the ModeChanged autocommand, which could potentially free the wp pointer which was valid before now became stale and points to now freed memory. So before calling win_enter(), let's verify one more time, that the wp pointer still points to a valid window structure. Reported by @henices, thanks! Signed-off-by: Christian Brabandt <cb@256bit.org>

#!/bin/sh
# toolcheck -- check for tools that have severe bugs. Good that all the buggy
#	       tools identify by version numbers. This is the spirit of GNU :-)
#
# 24.7.95 jw.

retval=0
reply="`sh -version -c exit 2>&1 < /dev/null`"
case "$reply" in
	GNU*1.14.3*)
		echo "- sh is	'$reply'";
		echo "  CAUTION: This shell has a buggy 'trap' command.";
		echo "           The configure script may fail silently.";
		retval=1;
		;;
	GNU*)
		echo "- sh is	'$reply' - probably OK.";
		;;
	*)	;;
esac

reply="`sed --version 2>&1 < /dev/null`"
case "$reply" in
	GNU\ sed\ version\ 2.0[34])
		echo "- sed is	'$reply'";
		echo "  CAUTION: This sed cannot configure screen properly."
		retval=1;
		;;
	GNU\ sed\ version\ 2.05|GNU\ sed\ version\ 2.03\ kevin)
		echo "- sed is	'$reply' - good.";
		;;
	GNU*)	echo "- sed is	'$reply'.";
		;;
	*)	;;
esac
exit $retval