#8089: Implementation of GHC.Event.Poll.poll is broken due to bad coercion -------------------------------+------------------------------------------- Reporter: merijn | Owner: Type: bug | Status: patch Priority: normal | Milestone: Component: | Version: 7.6.3 libraries/base | Keywords: patch Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Easy (less than 1 hour) Unknown/Multiple | Blocked By: Type of failure: Runtime | Related Tickets: crash | Test Case: | Blocking: | -------------------------------+------------------------------------------- Comment (by merijn): Previously patch is not sufficiently paranoid. It just moves the underflow from architectures where Int is smaller than CInt to architectures where CInt is smaller than Int. Because the `fromIntegral (maxBound :: CInt) :: Int` conversion underflows in the computation of `maxPollTimeout`. New patch deals with this by taking the max of `maxBound :: Int` and `fromIntegral (maxBound :: CInt) :: Int)`, as a result if the conversion from `maxBound :: CInt` to Int underflows the `maxPollTimeout` is turned into "maxBound :: Int", which is sufficient, as the poll function can't receive time outs bigger than that anyway. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8089#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler