Handle zero size non-fixed arrays better
In these cases the the size of the container is 0, and we don't have a frame offset table.
Also, in this case the validation can fail because g_variant_get_data() can return NULL.
In these cases the the size of the container is 0, and we don't have a frame offset table.
Also, in this case the validation can fail because g_variant_get_data() can return NULL.