If I have a Gee.HashMap and access its .values property, the generated C code will (correctly) call gee_abstract_map_get_values(). However, the object passed to that call will be cast to (GeeMap*) (which is the interface implemented by GeeAbstractMap) — it should instead be cast to (GeeAbstractMap*).

This causes GCC to print the following warning, specifying that we’re violating the C type system:

backend-store.c: In function '_folks_backend_store_get_modules_from_dir_co':
backend-store.c:2636:8: warning: passing argument 1 of 'gee_abstract_map_get_entries' from incompatible pointer type [enabled by default]
        _data_->_tmp39_ = gee_abstract_map_get_entries ((GeeMap*) G_TYPE_CHECK_INSTANCE_CAST (_data_->_tmp38_, GEE_TYPE_HASH_MAP, GeeHashMap));
        ^
In file included from backend-store.c:30:0:
/opt/gnome3/build/include/gee-0.8/gee.h:1457:9: note: expected 'struct GeeAbstractMap *' but argument is of type 'struct GeeMap *'


Test case coming.

This is with Vala 0.22.0.26-f79fe.