[GHC] #11695: On GHCi prompt the arrow (movement) keys create strange character sequences

[GHC]

#11695: On GHCi prompt the arrow (movement) keys create strange character sequences
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        Reporter:  heisenbug     |                Owner:
            Type:  bug           |               Status:  new
        Priority:  normal        |            Milestone:
       Component:  GHCi          |              Version:  8.1
      Resolution:                |             Keywords:
Operating System:  Linux         |         Architecture:  x86_64 (amd64)
 Type of failure:  None/Unknown  |            Test Case:
      Blocked By:                |             Blocking:
 Related Tickets:                |  Differential Rev(s):
       Wiki Page:                |
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Comment (by heisenbug):

 I did some experiments: doing it in an `ssh` session (to the very same
 machine) from a Windows laptop does not trigger the bug.

 I should say that the RHEL box is a server, `$DISPLAY` is a `vnc` session
 on different a login box. So there is more IO triggered on the `ghci`
 machine than one would assume.

 I did the same thing (wandering around in a block of "mmmmmm"), with
 `python` repl. No problems. So it mist be a `ghci` thing:
 {{{
 $ ghci
 GHCi, version 7.11.20150407: http://www.haskell.org/ghc/  :? for help
 *Main>
 mmmmmmmmmmmmmmmmmmmmmmmmmmmmODmmmmmmOCmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmCmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmCmmmmmmmmmmmmmmmmmmmmmOODDmmmOCmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmOCmmmmmmmmmmmmDmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmOCmmCmmm

 <interactive>:2:1:
     Not in scope:
 ?mmmmmmmmmmmmmmmmmmmmmmmmmmmmODmmmmmmOCmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmCmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmCmmmmmmmmmmmmmmmmmmmmmOODDmmmOCmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmOCmmmmmmmmmmmmDmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmOCmmCmmm?
 *Main> :q
 Leaving GHCi.
 $ python
 Python 2.3.7 (#1, Nov  3 2010, 17:47:44)
 [GCC 3.4.6] on linux2
 Type "help", "copyright", "credits" or "license" for more information.
 >>>
 mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
 }}}

 Maybe this is some improper handling of `EINTR` (or such) ?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11695#comment:3>
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