#!/bin/sh

# Regression test: extending a copy-mode selection by cursor movement, with
# the view otherwise unmoved (no scrolling), must not retransmit an image
# whose row the cursor passes through.
#
# window_copy_write_one() (window-copy.c) used to write text/highlight
# styling directly over image-covered cells, which - since a character
# write typically clears whatever pixel content a terminal was showing
# there - erased the image with nothing to redraw it back in. Separately,
# window_copy_write_line()'s call to image_redraw_area() used to fire
# unconditionally on every redraw, so even after fixing the erasure, the
# image would still be needlessly recomposited (and briefly flash) on
# every single cursor step even though nothing about it had changed. See
# tmux-image-redraw-known-bugs.md for the full write-up.
#
# This is checked by counting DCS (\033P) sequences in the client's raw
# output during the cursor movement: with the fix, extending a selection
# without scrolling never touches the image, so none should appear.

. ./image-noflash-common.inc

# The image, at the top of the pane, followed by enough plain lines that the
# cursor can move down through it and past it without the view needing to
# scroll.
$TMUX new-session -d -s inner -x 40 -y 20 \
    "printf '$SIXEL_HEADER'; for i in \$(seq 1 15); do echo line\$i; done; exec sh" ||
	exit 1
sleep 0.5

[ "$($TMUX display-message -p '#{image_support}')" = 0 ] && exit 0
$TMUX set -as terminal-features ',*:sixel' || exit 1

start_capture 40 20
assert_image_reached
: >$TMP

# Enter copy-mode, scroll to the top (where the image is) and select down
# through it one cursor step at a time - the view does not need to scroll
# for any of this, since the image is already at the top of what is
# visible.
$TMUX copy-mode -t inner || fail "copy-mode failed"
$TMUX send-keys -X history-top || fail "history-top failed"
sleep 0.2
: >$TMP
$TMUX send-keys -X begin-selection || fail "begin-selection failed"
i=0
while [ $i -lt 6 ]; do
	$TMUX send-keys -X cursor-down || fail "cursor-down failed"
	sleep 0.15
	i=$((i + 1))
done
sleep 0.5

assert_no_retransmit "while just moving the selection cursor"

exit 0