hash.c: cut off if recursion

nobu · nobu · commit d503381ce8ac · 2013-11-26T13:43:40.000Z
* hash.c (rb_hash): cut off if recursion detected to get rid of stack overflow. [ruby-core:58567] [Bug ruby#9151] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43859 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
diff --git a/ChangeLog b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Nov 26 22:43:36 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* hash.c (rb_hash): cut off if recursion detected to get rid of stack
+	  overflow.  [ruby-core:58567] [Bug #9151]
+
 Tue Nov 26 20:02:39 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* test/ruby/test_settracefunc.rb: add tests for a_call/a_return
diff --git a/hash.c b/hash.c
@@ -76,10 +76,17 @@ rb_any_cmp(VALUE a, VALUE b)
     return !rb_eql(a, b);
 }
 
+static VALUE
+hash_recursive(VALUE obj, VALUE arg, int recurse)
+{
+    if (recurse) return INT2FIX(0);
+    return rb_funcallv(obj, id_hash, 0, 0);
+}
+
 VALUE
 rb_hash(VALUE obj)
 {
-    VALUE hval = rb_funcall(obj, id_hash, 0);
+    VALUE hval = rb_exec_recursive(hash_recursive, obj, 0);
   retry:
     switch (TYPE(hval)) {
       case T_FIXNUM:
diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
@@ -1060,6 +1060,20 @@ def test_inverse_hash
     end
   end
 
+  def test_recursive_hash_value
+    bug9151 = '[ruby-core:58567] [Bug #9151]'
+
+    s = Struct.new(:x) {def hash; [x,""].hash; end}
+    a = s.new
+    b = s.new
+    a.x = b
+    b.x = a
+    ah = assert_nothing_raised(SystemStackError, bug9151) {a.hash}
+    bh = assert_nothing_raised(SystemStackError, bug9151) {b.hash}
+    assert_equal(ah, bh, bug9151)
+    assert_not_equal([a,"hello"].hash, [b,"world"].hash, bug9151)
+  end
+
   class TestSubHash < TestHash
     class SubHash < Hash
     end
