re.c: non-regexp name reference

* re.c (rb_reg_regsub): other than regexp has no name references.
  [ruby-core:78686] [Bug #13042]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57098 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 6 insertions, 1 deletions

diff --git a/re.c b/re.c
index 17893dd8e8..063e6d15c8 100644
--- a/re.c
+++ b/re.c
@@ -3731,7 +3731,8 @@ rb_reg_regsub(VALUE str, VALUE src, struct re_registers *regs, VALUE regexp)
                 if (name_end < e) {
 		    VALUE n = rb_str_subseq(str, (long)(name - RSTRING_PTR(str)),
 					    (long)(name_end - name));
-		    if (!rb_enc_compatible(RREGEXP_SRC(regexp), n) ||
+		    if (NIL_P(regexp) ||
+			!rb_enc_compatible(RREGEXP_SRC(regexp), n) ||
 			(no = name_to_backref_number(regs, regexp, name, name_end)) < 1) {
 			name_to_backref_error(n);
 		    }
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index d2fbd00a1d..4dee245462 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -1598,6 +1598,10 @@ CODE
     assert_equal(S("Abc"), S("abc").sub("a") {m = $~; "A"})
     assert_equal(S("a"), m[0])
     assert_equal(/a/, m.regexp)
+    bug = '[ruby-core:78686] [Bug #13042] other than regexp has no name references'
+    assert_raise_with_message(IndexError, /oops/, bug) {
+      'hello'.gsub('hello', '\k<oops>')
+    }
   end
 
   def test_sub!