Modify Kernel#clone and Kernel#dup.

Kernel#clone, Kernel#dup:
 - 'iv' should not be shared with the original object,
   but it should be copied.

Kernel#clone:
 - 'mt' of singleton_class should be copied.

include/mruby/khash.h

@@ -61,6 +61,7 @@ static const uint8_t __m[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
   khint_t kh_put_##name(kh_##name##_t *h, khkey_t key);                 \
   void kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets);       \
   void kh_del_##name(kh_##name##_t *h, khint_t x);                      \
+  kh_##name##_t *kh_copy_##name(mrb_state *mrb, kh_##name##_t *h);
 
 /* define kh_xxx_funcs
 
@@ -179,6 +180,20 @@ static const uint8_t __m[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
   {                                                                     \
     h->d_flags[x/8] |= __m[x%8];                                        \
     h->size--;                                                          \
+  }                                                                     \
+  kh_##name##_t *kh_copy_##name(mrb_state *mrb, kh_##name##_t *h)       \
+  {                                                                     \
+    kh_##name##_t *h2;                                                  \
+    khiter_t k, k2;                                                     \
+                                                                        \
+    h2 = kh_init_##name(mrb);                                           \
+    for (k = kh_begin(h); k != kh_end(h); k++) {                        \
+      if (kh_exist(h, k)) {                                             \
+        k2 = kh_put_##name(h2, kh_key(h, k));                           \
+        kh_value(h2, k2) = kh_value(h, k);                              \
+      }                                                                 \
+    }                                                                   \
+    return h2;                                                          \
   }
 
 
@@ -191,6 +206,7 @@ static const uint8_t __m[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
 #define kh_put(name, h, k) kh_put_##name(h, k)
 #define kh_get(name, h, k) kh_get_##name(h, k)
 #define kh_del(name, h, k) kh_del_##name(h, k)
+#define kh_copy(name, mrb, h) kh_copy_##name(mrb, h)
 
 #define kh_exist(h, x) (!__ac_iseither((h)->e_flags, (h)->d_flags, (x)))
 #define kh_key(h, x) ((h)->keys[x])

src/kernel.c

@@ -338,7 +338,12 @@ mrb_singleton_class_clone(mrb_state *mrb, mrb_value obj)
       if (klass->iv) {
           clone->iv = klass->iv;
       }
-    clone->mt = kh_init(mt, mrb);
+      if (klass->mt) {
+          clone->mt = kh_copy(mt, mrb, klass->mt);
+      }
+      else {
+          clone->mt = kh_init(mt, mrb);
+      }
       clone->tt = MRB_TT_SCLASS;
       return clone;
   }
@@ -361,10 +366,11 @@ init_copy(mrb_state *mrb, mrb_value dest, mrb_value obj)
       case MRB_TT_CLASS:
       case MRB_TT_MODULE:
         if (ROBJECT(dest)->iv) {
+            kh_destroy(iv, ROBJECT(dest)->iv);
             ROBJECT(dest)->iv = 0;
         }
         if (ROBJECT(obj)->iv) {
-            ROBJECT(dest)->iv = ROBJECT(obj)->iv;
+            ROBJECT(dest)->iv = kh_copy(iv, mrb, ROBJECT(obj)->iv);
         }
         break;
 
@@ -446,9 +452,8 @@ mrb_obj_dup(mrb_state *mrb, mrb_value obj)
         mrb_raise(mrb, E_TYPE_ERROR, "can't dup %s", mrb_obj_classname(mrb, obj));
     }
     p = mrb_obj_alloc(mrb, mrb_type(obj), mrb_obj_class(mrb, obj));
-    //init_copy(dup, obj);
     dup = mrb_obj_value(p);
-    mrb_funcall(mrb, dup, "initialize_copy", 1, obj);
+    init_copy(mrb, dup, obj);
 
     return dup;
 }