Path: utzoo!news-server.csri.toronto.edu!rutgers!njin!princeton!grendel.Princeton.EDU
From: rhl@grendel.Princeton.EDU (Robert Lupton (the Good))
Newsgroups: comp.windows.x
Subject: Illegal databases confuse XrmParseCommand
Message-ID: <6990@idunno.Princeton.EDU>
Date: 9 Mar 91 04:00:28 GMT
Sender: news@idunno.Princeton.EDU
Organization: Princeton University
Lines: 35

With the MIT X11R4 server, passing a garbage XrmDatabase to XrmParseCommand
causes a bus error (NULL is OK). As XrmParseCommand is supposed to set
rather than modify a database this is a little surprising (I imagine
that it is cleaning up), and doesn't appear to be documented. 

This was a nasty bug to find --- it depended on the state of the stack left
by the main programme that this was a subroutine of.

			Robert

/********************************************************************/
#include <X11/Xlib.h>
#include <X11/Xresource.h>

static XrmOptionDescRec options[] = {
   {"-display",		".display",	 XrmoptionSepArg,	NULL},
};

int
main(ac,av)
int ac;
char *av[];
{
   char *option_type;
   XrmDatabase args_db;
   XrmValue value;
   
   XrmInitialize();

   args_db = (XrmDatabase)1;		/* point somewhere illegal... */
   XrmParseCommand(&args_db,options,1,av[0],&ac,av);
   XrmGetResource(args_db,"foo.display","",&option_type,&value);

   return(0);
}