* regcomp.c (noname_disable_map): don't optimize out group 0

  Ruby's Regexp doesn't allow normal numbered groups if the regexp
  has named groups. On such case it optimizes out related NT_ENCLOSE.
  But even on the case it can use \g<0>.
  This fix not to remove NT_ENCLOSE whose regnum is 0.
  [ruby-core:75828] [Bug #12454]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55562 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 13 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index a1b3c2a8f1..d42b9690de 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Sat Jul  2 04:26:14 2016  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* regcomp.c (noname_disable_map): don't optimize out group 0
+	  Ruby's Regexp doesn't allow normal numbered groups if the regexp
+	  has named groups. On such case it optimizes out related NT_ENCLOSE.
+	  But even on the case it can use \g<0>.
+	  This fix not to remove NT_ENCLOSE whose regnum is 0.
+	  [ruby-core:75828] [Bug #12454]
+
 Sat Jul  2 03:09:27 2016  Naohisa Goto  <ngotogenome@gmail.com>
 
 	* string.c: Partially reverts r55547 and r55555.
diff --git a/regcomp.c b/regcomp.c
index add0e8f458..869299cc37 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -1870,17 +1870,16 @@ noname_disable_map(Node** plink, GroupNumRemap* map, int* counter)
 	  (*counter)++;
 	  map[en->regnum].new_val = *counter;
 	  en->regnum = *counter;
-	  r = noname_disable_map(&(en->target), map, counter);
 	}
-	else {
+	else if (en->regnum != 0) {
 	  *plink = en->target;
 	  en->target = NULL_NODE;
 	  onig_node_free(node);
 	  r = noname_disable_map(plink, map, counter);
+	  break;
 	}
       }
-      else
-	r = noname_disable_map(&(en->target), map, counter);
+      r = noname_disable_map(&(en->target), map, counter);
     }
     break;
 
diff --git a/test/ruby/test_regexp.rb b/test/ruby/test_regexp.rb
index 66e2802a23..6cbfdb1a85 100644
--- a/test/ruby/test_regexp.rb
+++ b/test/ruby/test_regexp.rb
@@ -441,6 +441,7 @@ class TestRegexp < Test::Unit::TestCase
     assert_raise(RegexpError) { Regexp.new(")(") }
     assert_raise(RegexpError) { Regexp.new('[\\40000000000') }
     assert_raise(RegexpError) { Regexp.new('[\\600000000000.') }
+    assert_raise(RegexpError) { Regexp.new("((?<v>))\\g<0>") }
   end
 
   def test_unescape