From ce198a4ac75aa517e9553db3ab18b8df8947c0a0 Mon Sep 17 00:00:00 2001
From: florian <florian@openbsd.org>
Date: Wed, 12 Jul 2023 15:44:47 +0000
Subject: [PATCH] basename(3) can fail, prevent segfault in strlen(3). OK tb,
 sthen

---
 usr.bin/patch/pch.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/usr.bin/patch/pch.c b/usr.bin/patch/pch.c
index af1af7a86c5..a3e0a9cf5f8 100644
--- a/usr.bin/patch/pch.c
+++ b/usr.bin/patch/pch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pch.c,v 1.64 2023/07/12 11:26:13 tb Exp $	*/
+/*	$OpenBSD: pch.c,v 1.65 2023/07/12 15:44:47 florian Exp $	*/
 
 /*
  * patch - a program to apply diffs to original files
@@ -1422,7 +1422,7 @@ compare_names(const struct file_name *names, bool assume_exists)
 {
 	size_t min_components, min_baselen, min_len, tmp;
 	char *best = NULL;
-	char *path;
+	char *path, *bn;
 	int i;
 
 	/*
@@ -1443,7 +1443,10 @@ compare_names(const struct file_name *names, bool assume_exists)
 			min_components = tmp;
 			best = path;
 		}
-		if ((tmp = strlen(basename(path))) > min_baselen)
+		bn = basename(path);
+		if (bn == NULL)
+			continue;
+		if ((tmp = strlen(bn)) > min_baselen)
 			continue;
 		if (tmp < min_baselen) {
 			min_baselen = tmp;
-- 
2.20.1