refactoring around mrb_hash_new

include/mruby/hash.h

@@ -20,8 +20,8 @@ struct RHash {
 #define mrb_hash_ptr(v)    ((struct RHash*)((v).value.p))
 #define mrb_hash_value(p)  mrb_obj_value((void*)(p))
 
-mrb_value mrb_hash_new_capa(mrb_state*, size_t);
-mrb_value mrb_hash_new(mrb_state *mrb, int capa);
+mrb_value mrb_hash_new_capa(mrb_state*, int);
+mrb_value mrb_hash_new(mrb_state *mrb);
 
 void mrb_hash_set(mrb_state *mrb, mrb_value hash, mrb_value key, mrb_value val);
 mrb_value mrb_hash_get(mrb_state *mrb, mrb_value hash, mrb_value key);

src/hash.c

@@ -81,21 +81,23 @@ mrb_gc_free_ht(mrb_state *mrb, struct RHash *hash)
 
 
 mrb_value
-mrb_hash_new_capa(mrb_state *mrb, size_t capa)
+mrb_hash_new_capa(mrb_state *mrb, int capa)
 {
   struct RHash *h;
 
   h = (struct RHash*)mrb_obj_alloc(mrb, MRB_TT_HASH, mrb->hash_class);
   h->ht = kh_init(ht, mrb);
-  kh_resize(ht, h->ht, capa);
+  if (capa > 0) {
+    kh_resize(ht, h->ht, capa);
+  }
   h->iv = 0;
   return mrb_obj_value(h);
 }
 
 mrb_value
-mrb_hash_new(mrb_state *mrb, int capa)
+mrb_hash_new(mrb_state *mrb)
 {
-  return mrb_hash_new_capa(mrb, capa);
+  return mrb_hash_new_capa(mrb, 0);
 }
 
 mrb_value