>># 
>># 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: ftchbyts.m,v 1.5 92/06/11 17:34:41 rws Exp $
>># 
>>#
>>TITLE XFetchBytes CH10
>>ASSERTION A XFetchBytes-1
When cut buffer zero contains data, then a call to
XFetchBytes returns in the nbytes_return argument the number
of bytes stored in the buffer and returns a pointer to
storage allocated for the data, which can be freed with
XFree.
>>STRATEGY
Store some data in cut buffer zero using XStoreBuffer.
Obtain the data in cut buffer zero using XFetchBytes.
Verify that the data is correct.
Free the returned data using XFree.
>>ASSERTION A XFetchBytes-2
When cut buffer zero does not contain any data, then a call
to XFetchBytes sets the nbytes_return argument to zero, and
returns NULL.
>>STRATEGY
Set cut buffer to contain data using XStoreBytes.
Delete the property CUT_BUFFER0 from screen 0 of the display using XDeletePropery.
Obtain the contents of cut buffer 0 using XFetchBytes.
Verify that the call returned NULL.
Verify that the nbytes_return argument was set to zero.
