1 files changed, 31 insertions, 18 deletions

diff --git a/src/hash.c b/src/hash.c
index 6d176e80c..4a85fcec3 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -60,6 +60,7 @@ mrb_gc_mark_ht(mrb_state *mrb, struct RHash *hash)
   khiter_t k;
   khash_t(ht) *h = hash->ht;
 
+  if (!h) return;
   for (k = kh_begin(h); k != kh_end(h); k++)
     if (kh_exist(h, k)) {
       mrb_gc_mark_value(mrb, kh_key(h, k));
@@ -70,13 +71,14 @@ mrb_gc_mark_ht(mrb_state *mrb, struct RHash *hash)
 size_t
 mrb_gc_mark_ht_size(mrb_state *mrb, struct RHash *hash)
 {
+  if (!hash->ht) return 0;
   return kh_size(hash->ht)*2;
 }
 
 void
 mrb_gc_free_ht(mrb_state *mrb, struct RHash *hash)
 {
-  kh_destroy(ht, hash->ht);
+  if (hash->ht) kh_destroy(ht, hash->ht);
 }
 
 
@@ -106,9 +108,11 @@ mrb_hash_get(mrb_state *mrb, mrb_value hash, mrb_value key)
   khash_t(ht) *h = RHASH_TBL(hash);
   khiter_t k;
 
-  k = kh_get(ht, h, key);
-  if (k != kh_end(h))
-    return kh_value(h, k);
+  if (h) {
+    k = kh_get(ht, h, key);
+    if (k != kh_end(h))
+      return kh_value(h, k);
+  }
 
   /* not found */
   if (MRB_RHASH_PROCDEFAULT_P(hash)) {
@@ -142,6 +146,7 @@ mrb_hash_set(mrb_state *mrb, mrb_value hash, mrb_value key, mrb_value val) /* mr
   mrb_hash_modify(mrb, hash);
   h = RHASH_TBL(hash);
 
+  if (!h) h = RHASH_TBL(hash) = kh_init(ht, mrb);
   k = kh_get(ht, h, key);
   if (k == kh_end(h)) {
     /* expand */
@@ -167,11 +172,11 @@ mrb_hash_dup(mrb_state *mrb, mrb_value hash)
   khash_t(ht) *h, *ret_h;
   khiter_t k, ret_k;
 
+  h = RHASH_TBL(hash);
   ret = (struct RHash*)mrb_obj_alloc(mrb, MRB_TT_HASH, mrb->hash_class);
   ret->ht = kh_init(ht, mrb);
 
-  if (!RHASH_EMPTY_P(hash)) {
-    h = RHASH_TBL(hash);
+  if (kh_size(h) > 0) {
     ret_h = ret->ht;
 
     for (k = kh_begin(h); k != kh_end(h); k++) {
@@ -196,7 +201,7 @@ mrb_hash_tbl(mrb_state *mrb, mrb_value hash)
 {
   khash_t(ht) *h = RHASH_TBL(hash);
 
-  if (!RHASH_TBL(hash)) {
+  if (!h) {
     RHASH_TBL(hash) = kh_init(ht, mrb);
   }
   return h;
@@ -696,7 +701,7 @@ mrb_hash_clear(mrb_state *mrb, mrb_value hash)
 {
   khash_t(ht) *h = RHASH_TBL(hash);
 
-  kh_clear(ht, h);
+  if (h) kh_clear(ht, h);
   return hash;
 }
 
@@ -813,13 +818,12 @@ static mrb_value
 mrb_hash_empty_p(mrb_state *mrb, mrb_value self)
 {
   khash_t(ht) *h = RHASH_TBL(self);
-  khiter_t k;
+
   if (h) {
-    for (k = kh_begin(h); k != kh_end(h); k++)
-      if (kh_exist(h, k))
-        return mrb_false_value();
+    if (kh_size(h) == 0)
+      return mrb_true_value();
   }
-  return mrb_true_value();
+  return mrb_false_value();
 }
 
 /* 15.2.13.4.11 */
@@ -934,8 +938,10 @@ inspect_hash(mrb_state *mrb, mrb_value hash, int recur)
 static mrb_value
 mrb_hash_inspect(mrb_state *mrb, mrb_value hash)
 {
-  if (RHASH_EMPTY_P(hash))
-      return mrb_str_new_cstr(mrb, "{}");
+  khash_t(ht) *h = RHASH_TBL(hash);
+
+  if (!h || kh_size(h) == 0)
+    return mrb_str_new_cstr(mrb, "{}");
   return inspect_hash(mrb, hash, 0);
 }
 
@@ -1102,6 +1108,8 @@ mrb_hash_has_value(mrb_state *mrb, mrb_value hash)
 static mrb_value
 hash_equal(mrb_state *mrb, mrb_value hash1, mrb_value hash2, int eql)
 {
+  khash_t(ht) *h1, *h2;
+
   if (mrb_obj_equal(mrb, hash1, hash2)) return mrb_true_value();
   if (mrb_type(hash2) != MRB_TT_HASH) {
       if (!mrb_respond_to(mrb, hash2, mrb_intern(mrb, "to_hash"))) {
@@ -1112,10 +1120,15 @@ hash_equal(mrb_state *mrb, mrb_value hash1, mrb_value hash2, int eql)
       else
           return mrb_fixnum_value(mrb_equal(mrb, hash2, hash1));
   }
-  if (RHASH_SIZE(hash1) != RHASH_SIZE(hash2)) return mrb_false_value();
+  h1 = RHASH_TBL(hash1);
+  h2 = RHASH_TBL(hash2);
+  if (!h2) {
+    if (!h2)  return mrb_true_value();
+    return mrb_false_value();
+  }
+  if (!h2) return mrb_false_value();
+  if (kh_size(h1) != kh_size(h2)) return mrb_false_value();
   else {
-    khash_t(ht) *h1 = RHASH_TBL(hash1);
-    khash_t(ht) *h2 = RHASH_TBL(hash2);
     khiter_t k1, k2;
     mrb_value key;