From: Karel Zak <kzak@redhat.com>
Date: Thu, 6 Jun 2019 10:33:03 +0000 (+0200)
Subject: wall: make sure ut_line is not empty
X-Git-Tag: v2.34~33
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=33985f1149598e9d5740cc6b851d979e3a8b84a5;p=thirdparty%2Futil-linux.git

wall: make sure ut_line is not empty

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1711574
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/term-utils/wall.c b/term-utils/wall.c
index c606e63474..c3e89bab9f 100644
--- a/term-utils/wall.c
+++ b/term-utils/wall.c
@@ -250,10 +250,12 @@ int main(int argc, char **argv)
 		if (utmpptr->ut_type != USER_PROCESS)
 			continue;
 #endif
-		/* Joey Hess reports that use-sessreg in /etc/X11/wdm/
-		   produces ut_line entries like :0, and a write
-		   to /dev/:0 fails. */
-		if (utmpptr->ut_line[0] == ':')
+		/* Joey Hess reports that use-sessreg in /etc/X11/wdm/ produces
+		 * ut_line entries like :0, and a write to /dev/:0 fails.
+		 *
+		 * It also seems that some login manager may produce empty ut_line.
+		 */
+		if (!*utmpptr->ut_line || *utmpptr->ut_line == ':')
 			continue;
 
 		if (group_buf && !is_gr_member(utmpptr->ut_user, group_buf))