v=1234
v=$v$v$v$v
v=$v$v$v$v
v=$v$v$v$v
#v=$v$v$v$v
v=beginlong$v$v$v${v}endlong
result=$(ENV= HISTFILE=/dev/null script -q /dev/null ${SH} +m -i -o emacs <<EOF
printf '%s\n' "$v"
printf 'running %s\n' fc; fc -l
EOF
)
case $result in
	*'running fc'*beginlong*endlong*) ;;
	*)
		set -x
		: result is "$result"
		exit 2
esac
result=${result#*running fc}
result=${result#*beginlong}
result=${result%endlong*}
reflected=beginlong${result}endlong
if [ "$v" != "$reflected" ]; then
	set -x
	: expected "$v" reflected "$reflected"
	exit 3
fi