Should not make empty strings shared; fix
MODIFY
src/string.c
src/string.c
@@ -423,7 +423,7 @@ byte_subseq(mrb_state *mrb, mrb_value str, mrb_int beg, mrb_int len)
mrb_shared_string *shared;
orig = mrb_str_ptr(str);
- if (RSTR_EMBED_P(orig)) {
+ if (RSTR_EMBED_P(orig) || RSTR_LEN(orig) == 0) {
s = str_new(mrb, orig->as.ary+beg, len);
}
else {

Should not make empty strings shared; fix #3407