Shift + F3 Key Event not read.

[thinkingreed]

Shift + F3 Key Event not read.
Shift + F2 and Shift + F4 are read correctly.

■ Verification environment
・ Ubuntu 20.04
・ Ubuntu20.04 on WSL
・ Ubuntu 18.04

■ Program
Implemented as in the example below.
crossterm/examples/event-stream-tokio.rs

Sorry to trouble you, but please confirm.

[TimonPost]

I validated it, it seems true that SHIFT + F3 is not correctly handled. The other F keys seem to behave perfectly.

There must be something wrong at one the following places:

https://github.com/crossterm-rs/crossterm/blob/master/src/event/sys/unix/parse.rs#L223
https://github.com/crossterm-rs/crossterm/blob/master/src/event/sys/unix/parse.rs#L259
https://github.com/crossterm-rs/crossterm/blob/master/src/event/sys/unix/parse.rs#L51

I can not see directly where this problem comes from, for that we need to debug and print the ESCAPE CODE SHIFT + F3 generates.

[thinkingreed]

I understand. Thank you for watching.
I will also analyze the weekend.

[MitMaro]

Did some digging into this tonight:

The issue seems to stem from the match here:

crossterm/src/event/sys/unix/parse.rs

Line 162 in f7063d9

match buffer[buffer.len() - 1] {

On my system at least, Shift + F3 produces a buffer of [27, 91, 49, 59, 50, 82], which incorrectly matches the b'R' arm of the match.

This matches the CSI for the cursor position, I'm not sure how this can be handled.

[thinkingreed]

As @MitMaro says, b'R'=> on line 162 is determined first, which seems to be a problem.
This is a rough fix, but you can avoid it by making the following fix.

        b'R'=> parse_csi_cursor_position (buffer),       
                   ↓↓↓↓↓↓↓↓↓↓↓
         b'R' => {
             let s = std::str::from_utf8(&buffer[2..buffer.len() - 1])
                 .map_err(|_| could_not_parse_event_error())?;
             let mut split = s.split(';');
             let y = next_parsed::<u16>(&mut split)?;
             let x = next_parsed::<u16>(&mut split)?;
             return if parse_modifiers(y as u8) == KeyModifiers::SHIFT && x == 2 {
                 parse_csi_modifier_key_code(buffer)
             } else {
                 parse_csi_cursor_position(buffer)
             };
         }

If you can avoid duplication of control code for cursor position acquisition,
it seems to be the best but difficult, and it seems more important to enable Shift + F3 than part of cursor position acquisition.
Please consider that.

[TimonPost]

Closing in favor of #685.