From 8f7cf1fdef1c890fa60809d2377890a0e7d32858 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Mon, 12 Oct 2026 11:40:17 +0100
Subject: [PATCH] Add ncv test.

---
 regress/ncv.sh | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 regress/ncv.sh

diff --git a/regress/ncv.sh b/regress/ncv.sh
new file mode 100644
index 000000000..c1aafeee7
--- /dev/null
+++ b/regress/ncv.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+# Check that attributes listed in ncv are not used with colours.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+TMUX2="$TEST_TMUX -LtestB$$ -f/dev/null"
+
+fail() {
+	echo "$*" >&2
+	exit 1
+}
+
+$TMUX kill-server 2>/dev/null
+$TMUX2 kill-server 2>/dev/null
+
+TMP=$(mktemp)
+trap "rm -f $TMP; $TMUX kill-server 2>/dev/null; $TMUX2 kill-server 2>/dev/null" 0 1 15
+
+$TMUX2 new -d -x20 -y5 \
+	"printf '\033[2;4mPLAIN\033[0m'; exec sleep 100" || exit 1
+$TMUX2 set -g status-left '' || exit 1
+$TMUX2 set -g status-right '' || exit 1
+$TMUX2 set -g status-format[0] \
+	'#[fg=black,bg=green,underscore,dim]MARK' || exit 1
+$TMUX2 set -as terminal-overrides ',screen:ncv=18' || exit 1
+
+$TMUX new -d -x20 -y5 || exit 1
+$TMUX set -g status off || exit 1
+$TMUX send -l "$TMUX2 attach" || exit 1
+$TMUX send Enter || exit 1
+sleep 1
+
+$TMUX capturep -pe >$TMP || exit 1
+ESC=$(printf '\033')
+grep -q "${ESC}\\[30m${ESC}\\[42mMARK" $TMP ||
+	fail "coloured status text missing"
+grep -q "${ESC}\\[2;4mPLAIN" $TMP ||
+	fail "attributes without colours were filtered"
+tail -1 $TMP | grep -q "${ESC}\\[4m" && fail "underline not filtered"
+tail -1 $TMP | grep -q "${ESC}\\[2m" && fail "dim not filtered"
+
+exit 0