File buffering isn't flushed at exit

[EyalLotem]

In C, there's an atexit handler to fflush all FILE* files.

In most other environments (e.g: Python files), file buffers are flushed in a graceful exit. With GHC 6.12.1, they aren't.

[EyalLotem]

Small program to reproduce the bug

[igloo]

This is an example of how finalizers aren't guaranteed to be run. If you use withFile then the handle will be closed and the data written, even if there is an exception:

import System.IO

main = withFile "test.txt" WriteMode $ \h ->
       hPutStrLn h "Hello world"