hash.c: fix WB miss issue in Hash#replace

* hash.c (rb_hash_replace): add a write barrier to fix GC mark miss on
  hashes using Hash#replace [Bug #9226] [ruby-core:58948]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44060 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 16 deletions

diff --git a/hash.c b/hash.c
index 1321b83191..7e18a4049a 100644
--- a/hash.c
+++ b/hash.c
@@ -1412,22 +1412,9 @@ rb_hash_replace(VALUE hash, VALUE hash2)
 
     table2 = RHASH(hash2)->ntbl;
 
-    if (RHASH_EMPTY_P(hash2)) {
-	rb_hash_clear(hash);
-	if (table2) hash_tbl(hash)->type = table2->type;
-	return hash;
-    }
-
-    if (RHASH_ITER_LEV(hash) > 0) {
-	rb_hash_clear(hash);
-	hash_tbl(hash)->type = table2->type;
-	rb_hash_foreach(hash2, replace_i, hash);
-    }
-    else {
-	st_table *old_table = RHASH(hash)->ntbl;
-	if (old_table) st_free_table(old_table);
-	RHASH(hash)->ntbl = st_copy(table2);
-    }
+    rb_hash_clear(hash);
+    hash_tbl(hash)->type = table2->type;
+    rb_hash_foreach(hash2, replace_i, hash);
 
     return hash;
 }