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From: thomas@mipsbx.nac.dec.com (Matt Thomas)
Newsgroups: comp.unix.ultrix
Subject: Re: DS3100: buggy cc
Message-ID: <2795@shlump.dec.com>
Date: 6 Jun 89 15:12:41 GMT
References: <1211@ttds.UUCP> <1207@ttds.UUCP>
Sender: news@shlump.dec.com
Reply-To: thomas@decwrl.dec.com
Organization: Digital Equipment Corporation
Lines: 27

> I have not got any responses on my query yet and my problem remains. In the
> meantime I have been able to extract the essence of the bug and put it into a
> small example which is included below. What can possibly go wrong??? 

You have a bug in your program.

>[most of progam deleted]
>
> do_nextevent()
> {
> 	XAnyEvent e;
> 
> 	XNextEvent(display, &e);
> }

XNextEvent takes a pointer to a XEvent as the second parameter, not a 
pointer to XAnyEvent.  The structure XAnyEvent is smaller than XEvent
so when XNextEvent copies the event into *e, part fo the stack is over-
written causing the segmentation fault.

Changing XAnyEvent e to XEvent e will make the program work correctly.

-- 
Matt Thomas                     Internet:   thomas@decwrl.dec.com
DECnet-Ultrix Development       UUCP:       ...!decwrl!thomas
Digital Equipment Corporation   Disclaimer: This message reflects my own
Littleton, MA                               warped views, etc.