* hash.c (rb_hash_rehash): fix to free new st_table when exception

  is raised in do_hash(). [Bug #9187]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43942 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 32 insertions, 7 deletions

diff --git a/hash.c b/hash.c
index e347c79192..d312325981 100644
--- a/hash.c
+++ b/hash.c
@@ -576,6 +576,11 @@ rb_hash_s_try_convert(VALUE dummy, VALUE hash)
     return rb_check_hash_type(hash);
 }
 
+struct rehash_arg {
+    VALUE hash;
+    st_table *tbl;
+};
+
 static int
 rb_hash_rehash_i(VALUE key, VALUE value, VALUE arg)
 {
@@ -585,6 +590,14 @@ rb_hash_rehash_i(VALUE key, VALUE value, VALUE arg)
     return ST_CONTINUE;
 }
 
+static VALUE
+rehash_func(VALUE arg)
+{
+    struct rehash_arg *p = (struct rehash_arg *)arg;
+    rb_hash_foreach(p->hash, rb_hash_rehash_i, (VALUE)p->tbl);
+    return Qnil;
+}
+
 /*
  *  call-seq:
  *     hsh.rehash -> hsh
@@ -608,18 +621,30 @@ rb_hash_rehash_i(VALUE key, VALUE value, VALUE arg)
 static VALUE
 rb_hash_rehash(VALUE hash)
 {
-    st_table *tbl;
+    int state;
+    struct rehash_arg arg;
+    st_table *new_tbl, *old_tbl = RHASH(hash)->ntbl;
 
     if (RHASH_ITER_LEV(hash) > 0) {
 	rb_raise(rb_eRuntimeError, "rehash during iteration");
     }
     rb_hash_modify_check(hash);
-    if (!RHASH(hash)->ntbl)
-        return hash;
-    tbl = st_init_table_with_size(RHASH(hash)->ntbl->type, RHASH(hash)->ntbl->num_entries);
-    rb_hash_foreach(hash, rb_hash_rehash_i, (VALUE)tbl);
-    st_free_table(RHASH(hash)->ntbl);
-    RHASH(hash)->ntbl = tbl;
+    if (!old_tbl) return hash;
+
+    new_tbl = st_init_table_with_size(old_tbl->type, old_tbl->num_entries);
+    arg.hash = hash;
+    arg.tbl = new_tbl;
+
+    rb_protect(rehash_func, (VALUE)&arg, &state);
+
+    if (state) {
+	st_free_table(new_tbl);
+	rb_jump_tag(state);
+    }
+    else {
+	st_free_table(RHASH(hash)->ntbl);
+	RHASH(hash)->ntbl = new_tbl;
+    }
 
     return hash;
 }