From 51355bea706899deaf47a3ca7092d7cf468437b2 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Fri, 19 Jun 2020 10:06:25 +0200
Subject: [PATCH] lib/sysfs: fix prefix use in sysfs_devname_is_hidden()

Addresses: https://github.com/karelzak/util-linux/issues/1062
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 lib/sysfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/sysfs.c b/lib/sysfs.c
index 38e99c05c..5b4de2cad 100644
--- a/lib/sysfs.c
+++ b/lib/sysfs.c
@@ -847,6 +847,9 @@ int sysfs_devname_is_hidden(const char *prefix, const char *name)
 
 	if (strncmp("/dev/", name, 5) == 0)
 		return 0;
+
+	if (!prefix)
+		prefix = "";
 	/*
 	 * Create path to /sys/block/<name>/hidden
 	 */