>># 
>># Copyright 1990, 1991 by the Massachusetts Institute of Technology and
>># UniSoft Group Limited.
>># 
>># Permission to use, copy, modify, distribute, and sell this software and
>># its documentation for any purpose is hereby granted without fee,
>># provided that the above copyright notice appear in all copies and that
>># both that copyright notice and this permission notice appear in
>># supporting documentation, and that the names of MIT and UniSoft not be
>># used in advertising or publicity pertaining to distribution of the
>># software without specific, written prior permission.  MIT and UniSoft
>># make no representations about the suitability of this software for any
>># purpose.  It is provided "as is" without express or implied warranty.
>># 
>># $XConsortium: gtvslinf.m,v 1.5 92/06/11 17:35:54 rws Exp $
>># 
>>#
>>TITLE XGetVisualInfo CH10
>>ASSERTION A XGetVisualInfo-1
A call to XGetVisualInfo returns the list of XVisualInfo
structures, which can be freed by XFree, which match those
components of the vinfo_template argument specified by the
vinfo_mask argument, and returns the number of such
structures in the nitems_return argument.
>>STRATEGY
Initialise the list of class/depth pairs from parameter XT_VISUAL_CLASSES.
Obtain list of all visuals for the screen.
Verify that XGetVisualInfo does not return NULL (should be at least one visual).
Verify that XGetVisualInfo returns at least one visual for each class/depth pair
  specified in parameter XT_VISUAL_CLASSES.
Verify that the list returned matches those in XT_VISUAL_CLASSES.
Verify that each visual can be selected using VisualIDMask.
Verify that each visual can be selected using VisualScreenMask.
Verify that each visual can be selected using VisualDepthMask.
Verify that each visual can be selected using VisualClassMask.
Verify that each visual can be selected using
  VisualScreenMask|VisualDepthMask|VisualClassMask.
Verify that each visual can be selected using VisualRedMaskMask.
Verify that each visual can be selected using VisualGreenMaskMask.
Verify that each visual can be selected using VisualBlueMaskMask.
Verify that each visual can be selected using VisualColormapSizeMask.
Verify that each visual can be selected using VisualBitsPerRGBMask.
Verify that each visual can be selected using
  VisualBitsPerRGBMask|VisualColormapSizeMask.
Verify that each visual can be selected using VisualAllMask.
Free the list of all visuals using XFree.
>>ASSERTION A XGetVisualInfo-2
When no visuals match the template specified by the
vinfo_mask and vinfo_template arguments, then a call to
XGetVisualInfo returns NULL.
>>STRATEGY
Obtain list of all visuals for the screen.
Initialise visual template to first visual returned.
Call XGetVisualInfo with VisualDepthMask and depth 0.
Verify that number of matching visuals is set to 0.
Verify that XGetVisualInfo returns NULL.
>>ASSERTION B XGetVisualInfo-3
When sufficient storage cannot be allocated, then a call to
XGetVisualInfo returns NULL.
>>STRATEGY
Report UNTESTED
