use frozen string of symbols

* range.c (range_step, range_each): String#upto should never
  modifies the receiver, use frozen strings to enumerate symbols.

* re.c (reg_operand): matching target is not modified.

* ext/socket/constants.c (constant_arg): str_to_int never modifies
  argument strings.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50306 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/re.c b/re.c
index 7e789f56df..207a77d272 100644
--- a/re.c
+++ b/re.c
@@ -2753,7 +2753,7 @@ static VALUE
 reg_operand(VALUE s, int check)
 {
     if (SYMBOL_P(s)) {
-	return rb_sym_to_s(s);
+	return rb_sym2str(s);
     }
     else {
 	return (check ? rb_str_to_str : rb_check_string_type)(s);