From b2e2fe824dbea78585946a229d09b784fb567acf Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Mon, 13 Jul 2026 11:32:28 +0100
Subject: [PATCH] Add scroll regress.

---
 regress/copy-mode-selection-scroll.sh | 113 ++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 regress/copy-mode-selection-scroll.sh

diff --git a/regress/copy-mode-selection-scroll.sh b/regress/copy-mode-selection-scroll.sh
new file mode 100644
index 000000000..7e7aee9ce
--- /dev/null
+++ b/regress/copy-mode-selection-scroll.sh
@@ -0,0 +1,113 @@
+#!/bin/sh
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+TMUX2="$TEST_TMUX -LtestB$$ -f/dev/null"
+$TMUX kill-server 2>/dev/null
+$TMUX2 kill-server 2>/dev/null
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	$TMUX2 kill-server 2>/dev/null
+}
+fail()
+{
+	echo "$1"
+	cleanup
+	exit 1
+}
+expect_buffer()
+{
+	expected=$1
+	actual=$($TMUX show-buffer)
+	[ "$actual" = "$expected" ] ||
+		fail "unexpected buffer: expected [$expected], got [$actual]"
+}
+wheel()
+{
+	button=$1
+	col=$2
+	row=$3
+	seq=$(printf '\033[<%s;%s;%sM' "$button" "$col" "$row")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 1
+}
+trap cleanup 0
+trap 'exit 1' 1 2 3 15
+
+$TMUX new -d -x40 -y10 \
+	'i=0; while [ $i -lt 80 ]; do printf "line %02d xxxxxxxxxx\n" $i; i=$((i + 1)); done; cat' ||
+	exit 1
+$TMUX set -g window-size manual || exit 1
+$TMUX set -g mouse on || exit 1
+
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X history-top || exit 1
+$TMUX send-keys -N10 -X cursor-down || exit 1
+$TMUX send-keys -X start-of-line || exit 1
+$TMUX send-keys -X begin-selection || exit 1
+$TMUX send-keys -N2 -X cursor-down || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+
+initial=$(printf 'line 10 xxxxxxxxxx\nline 11 xxxxxxxxxx')
+expect_buffer "$initial"
+
+$TMUX send-keys -X stop-selection || exit 1
+$TMUX send-keys -N3 -X scroll-down || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$initial"
+
+$TMUX send-keys -N2 -X scroll-up || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$initial"
+
+$TMUX send-keys -X scroll-middle || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$initial"
+
+$TMUX send-keys -X scroll-bottom || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$initial"
+
+$TMUX send-keys -X scroll-top || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$initial"
+
+$TMUX send-keys -X recentre-top-bottom || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$initial"
+
+$TMUX send-keys -X other-end || exit 1
+$TMUX send-keys -X cursor-down || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+
+extended_end=$(printf 'line 10 xxxxxxxxxx\nline 11 xxxxxxxxxx\nline 12 xxxxxxxxxx')
+expect_buffer "$extended_end"
+
+$TMUX send-keys -X stop-selection || exit 1
+$TMUX send-keys -X other-end || exit 1
+$TMUX send-keys -X other-end || exit 1
+$TMUX send-keys -X cursor-up || exit 1
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+
+extended_start=$(printf 'line 09 xxxxxxxxxx\nline 10 xxxxxxxxxx\nline 11 xxxxxxxxxx\nline 12 xxxxxxxxxx')
+expect_buffer "$extended_start"
+
+$TMUX2 new-session -d -x40 -y10 "$TMUX attach" || exit 1
+sleep 1
+OUTER=$($TMUX2 list-panes -F '#{pane_id}' | head -1)
+[ -n "$OUTER" ] || fail "no outer pane"
+
+wheel 65 5 5
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$extended_start"
+
+wheel 64 5 5
+$TMUX send-keys -X copy-selection-no-clear || exit 1
+expect_buffer "$extended_start"
+
+exit 0