[PATCH] state: check return value of chown

[yeholmes at outlook.com]

From: Ye Holmes <yeholmes at outlook.com>

Output warning in case changing the ownership of ubus' home
directory has failed. Besides, this avoids treating unused
result warning as error by GCC (with glibc-2.31, version 10.2):

procd-2020-12-12-7f12c89d/state.c: In function 'state_enter':
procd-2020-12-12-7f12c89d/state.c:147:4: error: ignoring
  return value of 'chown' declared with attribute
  'warn_unused_result' [-Werror=unused-result]
  147 |    chown(p->pw_dir, p->pw_uid, p->pw_gid);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Ye Holmes <yeholmes at outlook.com>
---
 state.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/state.c b/state.c
index 44f56c6..d68776f 100644
--- a/state.c
+++ b/state.c
@@ -144,7 +144,8 @@ static void state_enter(void)
 		if (p) {
 			LOG("- ubus -\n");
 			mkdir(p->pw_dir, 0755);
-			chown(p->pw_dir, p->pw_uid, p->pw_gid);
+			if (chown(p->pw_dir, p->pw_uid, p->pw_gid))
+				fprintf(stderr, "Failed to change ownership for %s\n", p->pw_dir);
 		} else {
 			LOG("- ubus (running as root!) -\n");
 		}
-- 
2.25.1