basic/set: let set_put_strdup() create the set with string hash ops

If we're using a set with _put_strdup(), most of the time we want to use
string hash ops on the set, and free the strings when done. This defines
the appropriate a new string_hash_ops_free structure to automatically free
the keys when removing the set, and makes set_put_strdup() and set_put_strdupv()
instantiate the set with those hash ops.

hashmap_put_strdup() was already doing something similar.

(It is OK to instantiate the set earlier, possibly with a different hash ops
structure. set_put_strdup() will then use the existing set. It is also OK
to call set_free_free() instead of set_free() on a set with
string_hash_ops_free, the effect is the same, we're just overriding the
override of the cleanup function.)

No functional change intended.

1 files changed, 2 insertions, 6 deletions

diff --git a/src/shared/bus-util.c b/src/shared/bus-util.c
index df701a3bfe..c7611a6e85 100644
--- a/src/shared/bus-util.c
+++ b/src/shared/bus-util.c
@@ -1695,14 +1695,10 @@ int bus_introspect_implementations(
         if (impl != main_impl)
                 bus_introspect_implementation(&intro, impl);
 
-        _cleanup_set_free_free_ Set *nodes = NULL;
+        _cleanup_set_free_ Set *nodes = NULL;
 
         for (size_t i = 0; impl->children && impl->children[i]; i++) {
-                r = set_ensure_allocated(&nodes, &string_hash_ops);
-                if (r < 0)
-                        return log_oom();
-
-                r = set_put_strdup(nodes, impl->children[i]->path);
+                r = set_put_strdup(&nodes, impl->children[i]->path);
                 if (r < 0)
                         return log_oom();
         }