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From: mouse@lightning.mcrcim.mcgill.EDU (der Mouse)
Newsgroups: comp.windows.x
Subject: Re:  HELP needed with BadMatch error
Message-ID: <9103261112.AA05054@lightning.McRCIM.McGill.EDU>
Date: 26 Mar 91 11:12:15 GMT
Sender: tytso@athena.mit.edu (Theodore Y. Ts'o)
Organization: The Internet
Lines: 37

> The following program gives the following protocol error and I can't
> work out why.  Enlightenment would be greatly appreciated.  A
> sensible mechanism for fixing it would also be appreciated.

> X Error:  BadMatch, invalid parameter attributes
>   Request Major code 72 ()

Major request 72 is PutImage, as one would expect.

>     mask = XCreateImage(display, DefaultVisualOfScreen(screen),
> 			1, XYBitmap, 0, 0,
> 			((cols>>3)+1)<<3, rows, 8, 0);
>     mask->data = malloc((mask->bytes_per_line+100) * (rows+100));

[...load mask's data...]

>     maskp = XCreatePixmap(display, RootWindowOfScreen(screen), cols, rows, 1);
>     XPutImage(display, maskp, DefaultGCOfScreen(screen), mask, 0, 0, 0, 0,
> 		cols, rows);

> Note that both the Image and the Pixmap have depth 1.

Are you by any chance on a non-1-bit server?  Because if so, the
default GC of the screen will not be of depth 1, so a BadMatch is to be
expected.

If that's not the problem, something weird is going on.  With four
changes, it builds fine here, and runs fine on a monochrome server and
dies as you describe on a color server.  (The four changes: delete the
#include of <Xm/DrawingA.h>, delete the extern from the declaration of
pm_progname, add an extern declaration for malloc, and add calls to
XCloseDisplay and exit at the end of main.)

					der Mouse

			old: mcgill-vision!mouse
			new: mouse@larry.mcrcim.mcgill.edu