*printf and zero size

Tom, did you implement this functionality in *printf?
The size may be given as zero to find out how many characters areneeded; in this case, the str argument is ignored.
Sprintf()andvsprintf() effectively assume an infinite size.
 

Looking at the code it doesn't seem supported.  Should it be added to
the limitations comment section?

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073