From 863f3ce0d050f005839f6aa41fe7bac5478a7b5e Mon Sep 17 00:00:00 2001
From: Tom Gundersen <teg@jklm.no>
Date: Fri, 19 Sep 2014 08:03:31 +0200
Subject: [PATCH] shared: wtmp-utmp - don't clear store_wtmp in
 utmp_put_dead_process()

Also modernize a few other things and add comments to explain CID #1237503
and CID #1237504.
---
 src/shared/utmp-wtmp.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/src/shared/utmp-wtmp.c b/src/shared/utmp-wtmp.c
index 30a0c031f3..31f13ec808 100644
--- a/src/shared/utmp-wtmp.c
+++ b/src/shared/utmp-wtmp.c
@@ -92,8 +92,6 @@ int utmp_get_runlevel(int *runlevel, int *previous) {
 static void init_timestamp(struct utmpx *store, usec_t t) {
         assert(store);
 
-        zero(*store);
-
         if (t <= 0)
                 t = now(CLOCK_REALTIME);
 
@@ -143,7 +141,7 @@ static int write_entry_wtmp(const struct utmpx *store) {
         assert(store);
 
         /* wtmp is a simple append-only file where each entry is
-        simply appended to * the end; i.e. basically a log. */
+        simply appended to the end; i.e. basically a log. */
 
         errno = 0;
         updwtmpx(_PATH_WTMPX, store);
@@ -172,7 +170,7 @@ static int write_entry_both(const struct utmpx *store) {
 }
 
 int utmp_put_shutdown(void) {
-        struct utmpx store;
+        struct utmpx store = {};
 
         init_entry(&store, 0);
 
@@ -183,7 +181,7 @@ int utmp_put_shutdown(void) {
 }
 
 int utmp_put_reboot(usec_t t) {
-        struct utmpx store;
+        struct utmpx store = {};
 
         init_entry(&store, t);
 
@@ -206,16 +204,17 @@ _pure_ static const char *sanitize_id(const char *id) {
 }
 
 int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line) {
-        struct utmpx store;
+        struct utmpx store = {
+                .ut_type = INIT_PROCESS,
+                .ut_pid = pid,
+                .ut_session = sid,
+        };
 
         assert(id);
 
         init_timestamp(&store, 0);
 
-        store.ut_type = INIT_PROCESS;
-        store.ut_pid = pid;
-        store.ut_session = sid;
-
+        /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */
         strncpy(store.ut_id, sanitize_id(id), sizeof(store.ut_id));
 
         if (line)
@@ -225,14 +224,15 @@ int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line
 }
 
 int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
-        struct utmpx lookup, store, store_wtmp, *found;
+        struct utmpx lookup = {
+                .ut_type = INIT_PROCESS /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */
+        }, store, store_wtmp, *found;
 
         assert(id);
 
         setutxent();
 
-        zero(lookup);
-        lookup.ut_type = INIT_PROCESS; /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */
+        /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */
         strncpy(lookup.ut_id, sanitize_id(id), sizeof(lookup.ut_id));
 
         found = getutxid(&lookup);
@@ -260,7 +260,7 @@ int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
 
 
 int utmp_put_runlevel(int runlevel, int previous) {
-        struct utmpx store;
+        struct utmpx store = {};
         int r;
 
         assert(runlevel > 0);