logind: rework manager_get_{user|session}_by_pid() a bit

Let's make sure we always initialize the return value if we return
non-negative.

Just a matter of coding style: we should always initialize our return
values when we return >= 0, and leave them unclobbered if we return < 0.

diff --git a/src/login/logind-core.c b/src/login/logind-core.c
index 41b4d4d8d78300887b134c49407c9f9b895d0a6e..8c022cf0f1c388d7ba5066830967a16b7314d796 100644 (file)
--- a/src/login/logind-core.c
+++ b/src/login/logind-core.c
@@ -282,7 +282,7 @@ int manager_process_button_device(Manager *m, struct udev_device *d) {
         return 0;
 }
 
-int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session) {
+int manager_get_session_by_pid(Manager *m, pid_t pid, Session **ret) {
         _cleanup_free_ char *unit = NULL;
         Session *s;
         int r;
@@ -294,38 +294,51 @@ int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session) {
 
         r = cg_pid_get_unit(pid, &unit);
         if (r < 0)
-                return 0;
+                goto not_found;
 
         s = hashmap_get(m->session_units, unit);
         if (!s)
-                return 0;
+                goto not_found;
+
+        if (ret)
+                *ret = s;
 
-        if (session)
-                *session = s;
         return 1;
+
+not_found:
+        if (ret)
+                *ret = NULL;
+        return 0;
 }
 
-int manager_get_user_by_pid(Manager *m, pid_t pid, User **user) {
+int manager_get_user_by_pid(Manager *m, pid_t pid, User **ret) {
         _cleanup_free_ char *unit = NULL;
         User *u;
         int r;
 
         assert(m);
-        assert(user);
 
         if (!pid_is_valid(pid))
                 return -EINVAL;
 
         r = cg_pid_get_slice(pid, &unit);
         if (r < 0)
-                return 0;
+                goto not_found;
 
         u = hashmap_get(m->user_units, unit);
         if (!u)
-                return 0;
+                goto not_found;
+
+        if (ret)
+                *ret = u;
 
-        *user = u;
         return 1;
+
+not_found:
+        if (ret)
+                *ret = NULL;
+
+        return 0;
 }
 
 int manager_get_idle_hint(Manager *m, dual_timestamp *t) {