[comp.sys.mac.programmer] PBGetCatInfo bug??

cruff@ncar.ucar.edu (Craig Ruff) (07/01/91)

I've been trying to track down a sporadic (but often repeatable) bug in a
call to PBGetCatInfo.  According to all my documentation, I'm passing in
all the in-parameters:

pb.hFileInfo.ioCompletion = nil;
pb.hFileInfo.ioNamePtr = &Str255_variable;	(initialized to zero len)
pb.hFileInfo.ioVRefNum = some_volume_refnum;
pb.hFileInfo.ioFDirIndex = 1;
pb.hFileInfo.ioDirID = some_dirid;

I've single stepped through the MPW C (3.1) glue to the point of the FSDispatch
trap, and upon stepping over the trap, I get an illegal instruction error
at a bogus address.  The configuration:

	IIsi, 5MB, 6.0.7 or 7.0 (24 bit mode, no VM)

However, I assume the problem has been seen on other configurations too.
I've even tried zeroing the entire parameter block (no difference).
As far as I can see, everything is valid to this point.

Is there some parameter I'm missing?  Some obscure entry in a Tech Note?
This worked fine (Tar v2) until these recent systems.
-- 
Craig Ruff      	NCAR			cruff@ncar.ucar.edu
(303) 497-1211  	P.O. Box 3000
			Boulder, CO  80307