initialize_copy: copy destination object may not be intialized

src/time.c

@@ -496,6 +496,10 @@ mrb_time_initialize_copy(mrb_state *mrb, mrb_value copy)
   if (!mrb_obj_is_instance_of(mrb, src, mrb_obj_class(mrb, copy))) {
     mrb_raise(mrb, E_TYPE_ERROR, "wrong argument class");
   }
+  if (!DATA_PTR(copy)) {
+    DATA_PTR(copy) = mrb_malloc(mrb, sizeof(struct mrb_time));
+    DATA_TYPE(copy) = &mrb_time_type;
+  }
   memcpy(DATA_PTR(copy), DATA_PTR(src), sizeof(struct mrb_time));
   return copy;
 }

test/test_time.rb

@@ -43,7 +43,6 @@ assert("yday")    { t1.yday    ==  71             }
 assert("year")    { t1.year    ==  2011           }
 
 t2 = Time.at(7.0e6)
-t1.initialize_copy(t2)
-assert("initialize_copy") { t1 == t2 }
+assert("initialize_copy") { t2.clone == t2 }
 
 report()