shared: always call close() from nm_close() wrapper

The nm_close() wrapper should behave exactly the same as calling
close() directly. This is well known, documented behavior.

The only addition on top of that, should be the nm_assert() to catch
double-closing.

Prevously, when passing a negative file descriptor, we wouldn't properly
set errno. Also, the call would not show up in strace, which it should
(at least, if libc's close actually makes the syscall).

I would argue, that passing a negative file descriptor is a bug already
and we should never do that. Maybe we should even assert non-negative
fds. I don't do that now, because I am not sufficiently confident.
Anyway, the change should have not practical effect, because we
shouldn't actually pass negative fds already.

1 files changed, 5 insertions, 6 deletions

diff --git a/shared/nm-utils/nm-macros-internal.h b/shared/nm-utils/nm-macros-internal.h
index 2d62ba7d97..f4dca4b37a 100644
--- a/shared/nm-utils/nm-macros-internal.h
+++ b/shared/nm-utils/nm-macros-internal.h
@@ -1246,12 +1246,11 @@ nm_steal_fd (int *p_fd)
 static inline int
 nm_close (int fd)
 {
-	if (fd >= 0) {
-		if (close (fd) == 0)
-			return 0;
-		nm_assert (errno != EBADF);
-	}
-	return -1;
+	int r;
+
+	r = close (fd);
+	nm_assert (r != -1 || fd < 0 || errno != EBADF);
+	return r;
 }
 
 #endif /* __NM_MACROS_INTERNAL_H__ */