Yitzchak Gale wrote:
Quoth InteractiveUI.runGHCi:
case maybe_expr of Nothing -> do #if defined(mingw32_HOST_OS) -- The win32 Console API mutates the first character of -- type-ahead when reading from it in a non-buffered manner. Work -- around this by flushing the input buffer of type-ahead characters, -- but only if stdin is available. flushed <- io (IO.try (GHC.ConsoleHandler.flushConsole stdin)) case flushed of Left err | isDoesNotExistError err -> return () | otherwise -> io (ioError err) Right () -> return () #endif -- enter the interactive loop interactiveLoop is_tty show_prompt
Could this be related somehow?
This was a hack to work around similar behaviour when starting up GHCi, and hence Sigbjorn's comment on #831: "that's right; I did add a workaround in the end, see comments in ghci/InteractiveUI.hs:runGHCi. It's in both STABLE and HEAD; dunno if it scratches this particular itch though. Notice that my workaround is only applied upon startup, not in the REPL. => floating the hackery inward could just save the day. " The underlying bug is in the Windows CRT, or perhaps a deeper level. IIRC it exists on a bug tracker somewhere inside Microsoft... Cheers, Simon