// When USE_VTP is active, CSI sequences written through
// write_chars() are interpreted by the console's VTP parser,
// generating responses (e.g. DECRQM) that end up in the
- // input buffer as unwanted keystrokes. Discard them.
+ // input buffer as unwanted keystrokes. Parse the sequence
+ // and only pass through known safe ones (e.g. DECSCUSR for
+ // cursor shape), discard the rest.
if (USE_VTP)
{
int l = 2;
l++;
// skip the final byte (0x40-0x7E)
if (s + l < end && s[l] >= 0x40 && s[l] <= 0x7E)
+ {
+ // DECSCUSR (cursor style): pass through to terminal
+ if (s[l] == 'q')
+ vtp_printf("%.*s", l + 1, s);
l++;
+ }
len -= l - 1;
s += l;
}