Ctr-c doesn't work in ghci-6.8.1, probably related to #1922

In ghci-6.8.1, pressing Ctrl-c once during an evaluation has no influence, pressing it twice during the same evaluation results in

Prelude Data.List> foldl' (+) 0 [1 .. 20000000]
<interactive>: exception :: GhcException

and it only returns to the prompt after a third Ctrl-c

*** Exception: <<loop>>
Prelude Data.List>

However, then no more computations are performed,only ghci commands (:?, :i, :t, :q) are then processed. A complete sample session, Ctrl-c was pressed once in each of the first two evaluations, twice in the third, then once more to produce *** Exception: <<loop>> and return to the prompt. From then onwards, any expression typed at the prompt results in no activity until a further Ctrl-c is pressed.

dafis@linux:~> ghci
GHCi, version 6.8.1: http://www.haskell.org/ghc/  :? for help
Loading package base ... linking ... done.
Prelude> :set +s
Prelude> :m +Data.List
Prelude Data.List> foldl' (+) 0 [1 .. 10000000]
50000005000000
(4.47 secs, 1041858060 bytes)
Prelude Data.List> foldl' (+) 0 [1 .. 20000000]
200000010000000
(8.68 secs, 2081067868 bytes)
Prelude Data.List> foldl' (+) 0 [1 .. 20000000]
<interactive>: exception :: GhcException


*** Exception: <<loop>>
Prelude Data.List> foldl' (+) 0 [1 .. 20000000]

*** Exception: <<loop>>
Prelude Data.List> foldl' (+) 0 [1 .. 20]
*** Exception: <<loop>>
Prelude Data.List> :?
 Commands available from the prompt:

   <statement>                 evaluate/run <statement>
   :add <filename> ...         add module(s) to the current target set
   :browse [[*]<module>]       display the names defined by <module>
   :cd <dir>     Interrupted.
Prelude Data.List> :i foldl
foldl :: (a -> b -> a) -> a -> [b] -> a         -- Defined in GHC.List
Prelude Data.List> :t (+) . (^)
(+) . (^) :: (Integral b, Num a, Num (b -> a)) => a -> (b -> a) -> b -> a
Prelude Data.List> :q
Leaving GHCi.
dafis@linux:~>

Trac metadata

Trac field	Value
Version	6.8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	GHCi
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