Fix `mrb_str_to_str()` to handle symbols.
@@ -973,6 +973,8 @@ mrb_str_to_str(mrb_state *mrb, mrb_value str)
switch (mrb_type(str)) {
case MRB_TT_STRING:
return str;
+ case MRB_TT_SYMBOL:
+ return mrb_sym2str(mrb, mrb_symbol(str));
case MRB_TT_FIXNUM:
return mrb_fixnum_to_str(mrb, str, 10);
case MRB_TT_CLASS:
