tree-wide: return NULL from freeing functions

I started working on this because I wanted to change how
DEFINE_TRIVIAL_CLEANUP_FUNC is defined. Even independently of that change, it's
nice to make make things more consistent and predictable.

1 files changed, 5 insertions, 7 deletions

diff --git a/src/busctl/busctl.c b/src/busctl/busctl.c
index 142aba0b92..fde9240749 100644
--- a/src/busctl/busctl.c
+++ b/src/busctl/busctl.c
@@ -780,24 +780,22 @@ static int member_compare_funcp(Member * const *a, Member * const *b) {
         return member_compare_func(*a, *b);
 }
 
-static void member_free(Member *m) {
+static Member* member_free(Member *m) {
         if (!m)
-                return;
+                return NULL;
 
         free(m->interface);
         free(m->name);
         free(m->signature);
         free(m->result);
         free(m->value);
-        free(m);
+        return mfree(m);
 }
-
 DEFINE_TRIVIAL_CLEANUP_FUNC(Member*, member_free);
 
-static void member_set_free(Set *s) {
-        set_free_with_destructor(s, member_free);
+static Set* member_set_free(Set *s) {
+        return set_free_with_destructor(s, member_free);
 }
-
 DEFINE_TRIVIAL_CLEANUP_FUNC(Set*, member_set_free);
 
 static int on_interface(const char *interface, uint64_t flags, void *userdata) {