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>

diff --git a/lib/sysfs.c b/lib/sysfs.c
index 38e99c05c76ad4610b44611df4aefae8791094ef..5b4de2cad9c361d37f2ad4860bf1a0e5a4274672 100644 (file)
--- 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
         */