Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcvax!kth!draken!ttds!jonasn
From: jonasn@ttds.UUCP (Jonas Nygren)
Newsgroups: comp.unix.ultrix
Subject: Re: DS3100: buggy cc
Message-ID: <1211@ttds.UUCP>
Date: 6 Jun 89 14:36:33 GMT
References: <1207@ttds.UUCP>
Reply-To: jonasn@ttds.UUCP (Jonas Nygren)
Organization: The Royal Inst. of Techn., Stockholm
Lines: 60

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??? 

When prog, below, is run this is the result.

% prog
Segmentation fault (core dumped)
%

Why does XNextEvent overwrite yyy's return adress on the stack??? 

Any help is welcome.
Thanx in advance


---------------- Compile: cc -g2 prog.c -o prog -lX11

#include <X11/Xlib.h>

Display *display;
Screen *screen;
int screen_no;
Window rootwin;
typedef unsigned long   color;
color black,white;


yyy()
{
	do_nextevent();
}

main(){
	Window w;

	display = XOpenDisplay ("");
	screen = XDefaultScreenOfDisplay (display);
	screen_no = XDefaultScreen(display);
	rootwin = XDefaultRootWindow (display);
	black = XBlackPixelOfScreen (screen);
	white = XWhitePixelOfScreen (screen);

	w = XCreateSimpleWindow(display, rootwin,
				100, 100, 300, 300, 0, black, white);
	XSelectInput(display,w,ExposureMask);
	XMapRaised(display,w);

	yyy();

	XDestroyWindow(display,w);
	XCloseDisplay(display);
}

do_nextevent()
{
	XAnyEvent e;

	XNextEvent(display, &e);
}