>># 
>># 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: ftchbffr.m,v 1.7 92/06/11 17:34:34 rws Exp $
>># 
>>#
>>TITLE XFetchBuffer CH10
>>ASSERTION A XFetchBuffer-1
When the cut buffer specified by the buffer argument
contains data, then a call to XFetchBuffer 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
For each cut buffer 0..7:
   Set the buffer to contain data using XStoreBuffer.
For each cut buffer 0..7:
   Obtain the contents of the buffer using XFetchBuffer.
   Verify that the data is correct.
   Free the returned data using XFree.
>>ASSERTION A XFetchBuffer-2
When the cut buffer specified by the buffer argument does
not contain any data, then a call to XFetchBuffer sets the
nbytes_return argument to zero, and returns NULL.
>>STRATEGY
For each cut buffer 0..7:
   Set the buffer to contain data using XStoreBuffer.
For i in 0..7:
  Delete the property CUT_BUFFERi from screen 0 of the display using XDeletePropery.
For each cut buffer 0..7:
   Obtain the contents of the buffer using XFetchBuffer.
   Verify that the call returned NULL.
   Verify that the nbytes_return argument was set to zero.
