From c43dd625b672589778ab6f2fe9c3e665c4199245 Mon Sep 17 00:00:00 2001
From: naruse <naruse@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 24 May 2013 07:32:45 +0000
Subject: [PATCH] * ext/strscan/strscan.c (strscan_aref): raise error if given 
  name reference is not found.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40912 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog                          |  5 +++++
 ext/strscan/strscan.c              | 23 ++++++++++++++++++++---
 test/strscan/test_stringscanner.rb | 11 +++++++----
 3 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index b5ad689456..892aec8a88 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri May 24 16:31:23 2013  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* ext/strscan/strscan.c (strscan_aref): raise error if given
+	  name reference is not found.
+
 Fri May 24 15:48:18 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (after_gc_sweep, garbage_collect_body): do major GC (full GC)
diff --git a/ext/strscan/strscan.c b/ext/strscan/strscan.c
index 4623994612..983debe071 100644
--- a/ext/strscan/strscan.c
+++ b/ext/strscan/strscan.c
@@ -975,6 +975,25 @@ strscan_matched_size(VALUE self)
     return INT2NUM(p->regs.end[0] - p->regs.beg[0]);
 }
 
+static int
+name_to_backref_number(struct re_registers *regs, VALUE regexp, const char* name, const char* name_end)
+{
+    int num;
+
+    num = onig_name_to_backref_number(RREGEXP(regexp)->ptr,
+	(const unsigned char* )name, (const unsigned char* )name_end, regs);
+    if (num >= 1) {
+	return num;
+    }
+    else {
+	VALUE s = rb_str_new(name, (long )(name_end - name));
+	rb_raise(rb_eIndexError, "undefined group name reference: %s",
+				 StringValuePtr(s));
+    }
+
+    UNREACHABLE;
+}
+
 /*
  * call-seq: [](n)
  *
@@ -1019,9 +1038,7 @@ strscan_aref(VALUE self, VALUE idx)
         case T_STRING:
             name = StringValuePtr(idx);
         name_to_backref:
-            name_end = name + strlen(name);
-            i = onig_name_to_backref_number(RREGEXP(p->regex)->ptr,
-                (const unsigned char* )name, (const unsigned char* )name_end, &(p->regs));
+	    i = name_to_backref_number(&(p->regs), p->regex, name, name + strlen(name));
             break;
         default:
             i = NUM2LONG(idx);
diff --git a/test/strscan/test_stringscanner.rb b/test/strscan/test_stringscanner.rb
index 7f2e5c1ccd..be548d1938 100644
--- a/test/strscan/test_stringscanner.rb
+++ b/test/strscan/test_stringscanner.rb
@@ -402,6 +402,8 @@ class TestStringScanner < Test::Unit::TestCase
     assert_equal 'stra', s[-1]
     assert_equal 'stra', s[0]
     assert_nil           s[1]
+    assert_raise(IndexError) { s[:c] }
+    assert_raise(IndexError) { s['c'] }
 
     assert_equal false,  s[-1].tainted?
     assert_equal false,  s[0].tainted?
@@ -458,16 +460,17 @@ class TestStringScanner < Test::Unit::TestCase
     assert_equal true, s[3].tainted?
     assert_equal true, s[4].tainted?
 
-    s = StringScanner.new("foo bar")
-    s.scan /(?<a>(\w+)) (?<b>(\w+))/
+    s = StringScanner.new("foo bar baz")
+    s.scan /(?<a>\w+) (?<b>\w+) (\w+)/
     assert_equal 'foo', s[1]
     assert_equal 'bar', s[2]
+    assert_nil s[3]
     assert_equal 'foo', s[:a]
     assert_equal 'bar', s[:b]
-    assert_equal nil,   s[:c]
+    assert_raise(IndexError) { s[:c] }
     assert_equal 'foo', s['a']
     assert_equal 'bar', s['b']
-    assert_equal nil,   s['c']
+    assert_raise(IndexError) { s['c'] }
   end
 
   def test_pre_match