Re: launch feedback status update

[Benjamin Kahn <xkahn ximian com>]

Havoc,
	This looks good and well thought out.  (Although I agree with Rodney
that an X hack would be cleaner, it certainly would take a long time
before every version of X supported the launch feedback extension.  Of
course, this will take a long time to get into all the X toolkits as
well.)

	The following bothers me slightly:

> Launchers should attempt to detect launchee failures and end the
> launch sequence if appropriate; for example, if a launched application
> exits with a nonzero exit code, it would be a good idea to set
> _NET_LAUNCH_COMPLETE and end launch feedback. The launcher is
> responsible for displaying an error dialog to the user in this case.
> 
> Launchers should not however end feedback if a launched process exits
> normally, because the process may have been a wrapper script, may have
> asked an already-open application to create a new window, etc.
> 
> Only an external "launch manager" program should "time out" a launchee
> and decide to end launch feedback; the launcher application should
> never do this, it should only end the launch sequence if it has a good
> reason to believe the launchee exited abnormally.

	This means that launched applications which don't follow the new
protocol and don't open a new window won't work correctly.  Such
examples might be:

    /sbin/service httpd start
    xmms-control next-song
    old-xwrite -display some.host.com "hi!"

Etc.

	Basically, if a command exits with a zero-status, it should stop launch
feedback.