compile.c: defined? with empty expression

* compile.c (iseq_compile_each): fix of defined? with empty
  expression.  [ruby-core:53999] [Bug #8220]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40124 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 16 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index e809b06581..7e96cf8269 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Apr  5 19:39:52 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* compile.c (iseq_compile_each): fix of defined? with empty
+	  expression.  [ruby-core:53999] [Bug #8220]
+
 Fri Apr  5 13:22:59 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/curses/curses.c (Init_curses): fix implementation function,
diff --git a/compile.c b/compile.c
index 9360f5b791..65d01220e7 100644
--- a/compile.c
+++ b/compile.c
@@ -5175,7 +5175,12 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	break;
       }
       case NODE_DEFINED:{
-	if (!poped) {
+	if (poped) break;
+	if (!node->nd_head) {
+	    VALUE str = rb_iseq_defined_string(DEFINED_NIL);
+	    ADD_INSN1(ret, nd_line(node), putobject, str);
+	}
+	else {
 	    LABEL *lfinish[2];
 	    lfinish[0] = NEW_LABEL(line);
 	    lfinish[1] = 0;
diff --git a/test/ruby/test_syntax.rb b/test/ruby/test_syntax.rb
index 61507ecd83..895a4569fd 100644
--- a/test/ruby/test_syntax.rb
+++ b/test/ruby/test_syntax.rb
@@ -13,6 +13,11 @@ class TestSyntax < Test::Unit::TestCase
     eom
   end
 
+  def test_defined_empty_argument
+    bug8220 = '[ruby-core:53999] [Bug #8220]'
+    assert_ruby_status(%w[--disable-gem], 'puts defined? ()', bug8220)
+  end
+
   def test_must_ascii_compatible
     require 'tempfile'
     f = Tempfile.new("must_ac_")