From 4c9635b03d0acf140f65004be9d4822297ee5a35 Mon Sep 17 00:00:00 2001
From: Carlos Santos <casantos@datacom.com.br>
Date: Mon, 10 Dec 2018 17:27:16 -0200
Subject: [PATCH] Fix compilation of tacc.c with GCC 8

GCC 8 demands that the size of the string copied by strncpy be smaller
than the size of the destination to keep space for the trailibg '\0':

tacc.c:378:3: error: 'strncpy' specified bound 4 equals destination size [-Werror=stringop-truncation]
   strncpy(utmpx.ut_id, tty + C_STRLEN("tty"), sizeof(utmpx.ut_id));

Ensure that no more than sizeof(utmpx.ut_id) - 1 characters are copied
and that a trailing '\0' is stored.

Fixes:
  http://autobuild.buildroot.net/results/da6d150e470046c03c5f7463de045604e15e4a30/

Signed-off-by: Carlos Santos <casantos@datacom.com.br>
---
 tacc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tacc.c b/tacc.c
index f61e2d7..3c1a40c 100644
--- a/tacc.c
+++ b/tacc.c
@@ -375,7 +375,8 @@ int main(int argc, char **argv) {
 		utmpx.ut_type = USER_PROCESS;
 		utmpx.ut_pid = getpid();
 		xstrcpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
-		strncpy(utmpx.ut_id, tty + C_STRLEN("tty"), sizeof(utmpx.ut_id));
+		strncpy(utmpx.ut_id, tty + C_STRLEN("tty"), sizeof(utmpx.ut_id) - 1);
+		utmpx.ut_id[sizeof(utmpx.ut_id) - 1] = '\0';
 		xstrcpy(utmpx.ut_host, "dialup", sizeof(utmpx.ut_host));
 		utmpx.ut_tv.tv_sec = tv.tv_sec;
 		utmpx.ut_tv.tv_usec = tv.tv_usec;
-- 
2.14.5