Fixed a `String#squeeze` bug in handling `iso-8859-1` strings; ref
MODIFY
mrbgems/mruby-string-ext/src/string.c
mrbgems/mruby-string-ext/src/string.c
@@ -573,7 +573,7 @@ str_squeeze(mrb_state *mrb, mrb_value str, mrb_value v_pat)
else {
for (i=j=0; i<len; i++,j++) {
if (i>j) s[j] = s[i];
- if (s[i] == lastch) {
+ if (s[i] >= 0 && s[i] == lastch) {
flag_changed = TRUE;
j--;
}

Fixed a `String#squeeze` bug in handling `iso-8859-1` strings; ref #4127