From 668da3fc0ad7db1c9ef6206f83bf16249bfce091 Mon Sep 17 00:00:00 2001
From: Jakub Hrozek <jakub.hrozek@posteo.se>
Date: Sep 28 2018 08:37:05 +0000
Subject: Explicitly check the return value of getgrgid_r/getgrnam_r


Merges:
https://pagure.io/libuser/issue/21

An explicit return value check makes the job of static code analyzers
easier.

---

diff --git a/lib/config.c b/lib/config.c
index 29e7120..97221f7 100644
--- a/lib/config.c
+++ b/lib/config.c
@@ -672,6 +672,7 @@ handle_default_useradd_key(gpointer xkey, gpointer xvalue, gpointer xconfig)
 			char buf[LINE_MAX * 4];
 			intmax_t val;
 			char *p;
+			int rv;
 
 			errno = 0;
 			val = strtoimax(value, &p, 10);
@@ -679,8 +680,8 @@ handle_default_useradd_key(gpointer xkey, gpointer xvalue, gpointer xconfig)
 			    || (gid_t)val != val) {
 				struct group grp, *g;
 
-				getgrnam_r(value, &grp, buf, sizeof(buf), &g);
-				if (g != NULL)
+				rv = getgrnam_r(value, &grp, buf, sizeof(buf), &g);
+				if (rv == 0 && g != NULL)
 					value = g->gr_name;
 				/* else ignore the entry */
 			}
diff --git a/lib/user.c b/lib/user.c
index ad2bb09..8aa03b9 100644
--- a/lib/user.c
+++ b/lib/user.c
@@ -2060,13 +2060,14 @@ lu_get_first_unused_id(struct lu_context *ctx,
 		struct lu_error *error = NULL;
 		do {
 			struct group grp, *err;
+			int rv;
 
 			/* There may be read-only sources of user information
 			 * on the system, and we want to avoid allocating an ID
 			 * that's already in use by a service we can't write
 			 * to, so check with NSS first. */
-			getgrgid_r(id, &grp, buf, sizeof(buf), &err);
-			if (err == &grp) {
+			rv = getgrgid_r(id, &grp, buf, sizeof(buf), &err);
+			if (rv == 0 && err == &grp) {
 				id++;
 				continue;
 			}