Bug#429021: builtin echo command redirection misbehaves in detached scripts when terminal is closed

[Pierre-Philippe Coupard <pcoupard@skynet.be>]

The change is far from trivial or harmless, if it was intended. I had to 
rebuild a custom server I run in a hurry because it was flooding an IRC 
channel with log lines a backend bash script sent to stderr. And I can 
think of plenty of ways to trash files with this bug.

Anyway, thanks a lot Stéphane and Andreas for testing this!

Stephane Chazelas wrote:
> Now, I'm not sure if we can say that the new glibc behavior
> observed is bogus (other than it's different from the behavior
> observed in all the libcs I tried with). It is not a harmless
> change, for sure as it seems to have broken at least bash, zsh
> and possibly ksh93.
>
> Dmitry, you may find that whole thread at:
> http://groups.google.com/group/gnu.bash.bug/browse_thread/thread/e311bdd4f945a21e/621b7189217760f1
>
> Best regards,
> Stéphane
>
>
>