readline: splitted escape sequences are processed incorrectly

[rlidwka]

I'm running io.js inside LXC container console (lxc-console) in Ubuntu 14.04 terminal.

When I press and hold an arrow key, node.js sometimes receives escape sequences splitted into multiple chunks:

$ node -e 'process.stdin.setRawMode(true);process.stdin.on("data", function(d){console.log(d)})'
<Buffer 1b 5b 44>
<Buffer 1b 5b 44>
<Buffer 1b>
<Buffer 5b 44>
<Buffer 1b 5b 44>

Here you can see \x1b[D (arrow left) is broken into \x1b + [D.

Readline doesn't handle those, because it assumes that the entire escape sequence is contained within a data chunk. So it skips escape character itself, and [D is getting printed to the terminal:

$ node
> console.log('h[Dello world')

Here is a screenshot.

Trying to find a way to fix it at the moment. Any ideas?

[silverwind]

I have this too on one of my Windows machines while beeing ssh'ed into a RedHat box. Curiously, it doesn't happen on any other scenarios for me, but if it does, it hugely annoying to work the repl with that bug.

[piscisaureus]

There isn't a trivial fix for this, but generally speaking we'd need to turn this into a streaming parser.

[silverwind]

Any suitable userland parsers wo could borrow from?

[silverwind]

For some reason I fail to reproduce this on the one machine that was affected by this. Maybe there's a easier way than setting up a LXC container to reproduce?

[rlidwka]

Maybe there's a easier way than setting up a LXC container to reproduce?

You can press ESC, [ and D. In io.js repl it would be three separate keys, but in bash and other shells it would be one escape sequence representing left arrow. That's an easy way.

I'm trying to fix it in #1601

[silverwind]

Fixed by aed6bce