From 9d147116bcc5774de3e14f2636dd974e77666ddc Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Fri, 16 Oct 2026 13:01:40 +0100
Subject: [PATCH] Test for 5752.

---
 regress/tty-keys-colours-redraw.sh | 85 ++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 regress/tty-keys-colours-redraw.sh

diff --git a/regress/tty-keys-colours-redraw.sh b/regress/tty-keys-colours-redraw.sh
new file mode 100644
index 000000000..22a700579
--- /dev/null
+++ b/regress/tty-keys-colours-redraw.sh
@@ -0,0 +1,85 @@
+#!/bin/sh
+
+# A delayed OSC 11 reply must redraw theme colours without a status timer,
+# window rename, pane output or another command causing the redraw.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+python3 -B - "$TEST_TMUX" <<'PY'
+import fcntl
+import os
+import select
+import struct
+import subprocess
+import sys
+import termios
+import time
+
+tmux = sys.argv[1]
+server = [tmux, "-LtestColours%d" % os.getpid(), "-f/dev/null"]
+
+def run(*args, check=True):
+    p = subprocess.run(server + list(args), capture_output=True)
+    if check and p.returncode != 0:
+        raise RuntimeError("%r: %s" % (args, p.stderr.decode()))
+
+def read_output(timeout):
+    output = b""
+    deadline = time.monotonic() + timeout
+    while time.monotonic() < deadline:
+        remaining = max(0, deadline - time.monotonic())
+        if select.select([fd], [], [], min(.05, remaining))[0]:
+            output += os.read(fd, 65536)
+    return output
+
+def expect_redraw(colour, context):
+    output = b""
+    deadline = time.monotonic() + 3
+    while colour not in output or b"THEME" not in output:
+        assert time.monotonic() < deadline, (context, "missing redraw", output)
+        output += read_output(.05)
+    # Let the redraw finish before sending another report.
+    read_output(.2)
+
+pid = fd = None
+try:
+    run("new-session", "-d", "-s", "colours", "-x", "80", "-y", "24",
+        "sleep 100")
+    run("set-option", "-s", "theme", "detect")
+    run("set-option", "-s", "dark-theme-dark-grey", "red")
+    run("set-option", "-s", "light-theme-dark-grey", "green")
+    run("set-option", "-g", "automatic-rename", "off")
+    run("set-option", "-g", "status-interval", "0")
+    run("set-option", "-g", "status-style", "bg=themedarkgrey,fg=white")
+    run("set-option", "-g", "status-format[0]", "THEME")
+    pid, fd = os.forkpty()
+    if pid == 0:
+        os.environ["TERM"] = "xterm-256color"
+        os.environ.pop("TMUX", None)
+        fcntl.ioctl(0, termios.TIOCSWINSZ,
+            struct.pack("HHHH", 24, 80, 0, 0))
+        os.execv(tmux, server + ["attach-session", "-t", "colours"])
+
+    expect_redraw(b"\033[41m", "initial dark theme")
+    # No DSR 996 response is sent: OSC 11 alone must update the theme.
+    os.write(fd, b"\033]11;rgb:ffff/ffff/ffff\033\\")
+    expect_redraw(b"\033[42m", "delayed light background (ST)")
+    os.write(fd, b"\033]11;rgb:0000/0000/0000\007")
+    expect_redraw(b"\033[41m", "dark background (BEL)")
+
+    # An unchanged background and a foreground reply need no redraw.
+    for report in (b"\033]11;rgb:0000/0000/0000\007",
+                   b"\033]10;rgb:ffff/ffff/ffff\007"):
+        os.write(fd, report)
+        output = read_output(.3)
+        assert b"THEME" not in output, ("unnecessary redraw", report, output)
+finally:
+    run("kill-server", check=False)
+    if fd is not None:
+        os.close(fd)
+    if pid is not None:
+        os.waitpid(pid, 0)
+PY