> >Number:         5809
> >Category:       xsrc
> >Synopsis:       X server crashes unhelpfully
>
> >How-To-Repeat:
> 	Well, now that I know this is the problem my next guess is that it's
> 	because my libc is out of date, though I'm surprised that this would
> 	cause this particular result unless some #defines have changed their
> 	numeric values recently.

Which was the problem, and it was because #define's had changed,
because they didn't exist at all when the libc I had installed was
compiled. :)

So this problem only arises if you happen to install newer include
files, don't update your library, and then compile an X server, just
happening to cross the day _SC_PAGESIZE is added.  This is probably
rare. :)

I still think the patch should be applied, only because the code
behaves so badly if the return value is invalid...