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readline: splitted escape sequences are processed incorrectly #1403

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readline: splitted escape sequences are processed incorrectly#1403
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confirmed-bugIssues and PRs for confirmed bugs.readlineIssues and PRs related to the built-in readline module.

Description

@rlidwka
rlidwka
opened on Apr 12, 2015

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?

Activity

  1. brendanashworth
    added
    readlineIssues and PRs related to the built-in readline module.
    on Apr 12, 2015

  2. silverwind commented on Apr 12, 2015

    @silverwind
    silverwind
    on Apr 12, 2015
    Contributor

    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.

  3. silverwind
    added
    confirmed-bugIssues and PRs for confirmed bugs.
    on Apr 12, 2015

  4. piscisaureus commented on Apr 12, 2015

    @piscisaureus
    piscisaureus
    on Apr 12, 2015
    Contributor

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

  5. silverwind commented on Apr 13, 2015

    @silverwind
    silverwind
    on Apr 13, 2015
    Contributor

    Any suitable userland parsers wo could borrow from?

  6. brendanashworth
    added
    confirmed-bug
    and removed
    confirmed-bug
    on Apr 20, 2015

  7. silverwind commented on May 2, 2015

    @silverwind
    silverwind
    on May 2, 2015
    Contributor

    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?

  8. rlidwka
    added a commit that references this issue on May 3, 2015

    readline: turn emitKeys into a streaming parser

    3546151

  9. rlidwka commented on May 3, 2015

    @rlidwka
    rlidwka
    on May 3, 2015
    ContributorAuthor

    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

  10. rlidwka
    added a commit that references this issue on May 9, 2015

    readline: turn emitKeys into a streaming parser

    18728cc
  11. silverwind
    added a commit that references this issue on May 10, 2015

    readline: turn emitKeys into a streaming parser

    aed6bce

  12. silverwind commented on May 10, 2015

    @silverwind
    silverwind
    on May 10, 2015
    Contributor

    Fixed by aed6bce

  13. silverwind
    closed this as completedon May 10, 2015
  14. Fishrock123
    added a commit that references this issue on May 19, 2015

    readline: turn emitKeys into a streaming parser

    c212f8e
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