From 081983e3ad18baaecb5311bd82fc50f5b3e3e273 Mon Sep 17 00:00:00 2001
From: Christopher Wellons <wellons@nullprogram.com>
Date: Thu, 22 Oct 2026 21:08:02 -0400
Subject: [PATCH] Reject stty rows, cols, and columns on Windows

busybox-w32 recognized these settings but cannot set the window size.
The first pass checked the following number without consuming it, so
every use failed, and with nothing after them stty crashed on a null
pointer. Now they are rejected as invalid arguments.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 man/man1/stty.1                | 15 +++++++--------
 src/busybox/series             |  1 +
 src/busybox/stty-winsize.patch | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 8 deletions(-)
 create mode 100644 src/busybox/stty-winsize.patch

diff --git a/man/man1/stty.1 b/man/man1/stty.1
index 1792c26..11caf3c 100644
--- a/man/man1/stty.1
+++ b/man/man1/stty.1
@@ -112,8 +112,8 @@ The settings
 .BR cols ,
 and
 .BR columns ,
-which resize the window on Unix, are recognized but always fail:
-a number after one of them is reported as an invalid argument.
+which resize the window on Unix, are not supported and are rejected as
+invalid arguments.
 .SH OPTIONS
 .TP
 .B \-a
@@ -235,14 +235,13 @@ There is no way to save the current mode and restore it later, because
 .B \-g
 is not supported.
 .PP
-When
+busybox-w32 recognizes
 .BR rows ,
 .BR cols ,
-or
-.B columns
-is the last argument, with no number after it,
-.B stty
-crashes instead of reporting an error.
+and
+.BR columns ,
+but rejects the number after them, and crashes when nothing follows.
+w64devkit rejects them outright.
 .PP
 .BR ttysize (1)
 also prints the console size, prints the width first by default, and
diff --git a/src/busybox/series b/src/busybox/series
index 0478c0a..9bff76f 100644
--- a/src/busybox/series
+++ b/src/busybox/series
@@ -11,3 +11,4 @@ less-raw-sgr.patch
 bare-drive.patch
 rm-bare-drive.patch
 drop-test2.patch
+stty-winsize.patch
diff --git a/src/busybox/stty-winsize.patch b/src/busybox/stty-winsize.patch
new file mode 100644
index 0000000..2f3001e
--- /dev/null
+++ b/src/busybox/stty-winsize.patch
@@ -0,0 +1,33 @@
+On Windows, stty recognized rows, cols and columns as settings, though
+it cannot set the window size and its usage lists only size. The first
+pass checked the following number without consuming it, so "stty rows
+30" always failed with "invalid argument '30'", and "stty rows" with
+nothing after it dereferenced a null pointer and crashed. Recognize only
+size, so these are rejected as invalid arguments like other settings
+the Windows build lacks.
+
+--- a/coreutils/stty.c
++++ b/coreutils/stty.c
+@@ -1008,17 +1008,11 @@
+ 
+ static int find_param(const char *name)
+ {
+-	static const char params[] ALIGN1 =
+-		"rows\0"    /* 1 */
+-		"cols\0"    /* 2 */
+-		"columns\0" /* 3 */
+-		"size\0";    /* 4 */
+-	int i = index_in_strings(params, name) + 1;
+-	if (i == 0)
+-		return 0;
+-	if (i != 4)
+-		i |= 0x80;
+-	return i;
++	/* The window size cannot be set, so rows, cols and columns are
++	 * not settings: accepting them consumed no argument, and with
++	 * none following, dereferenced a null pointer.
++	 */
++	return strcmp(name, "size") == 0 ? param_size : 0;
+ }
+ #endif
+