Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!pasteur!ucbvax!decwrl!labrea!polya!kaufman
From: kaufman@polya.Stanford.EDU (Marc T. Kaufman)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Quickdraw Bug
Message-ID: <3178@polya.Stanford.EDU>
Date: 7 Jul 88 01:03:26 GMT
References: <3174@polya.Stanford.EDU> <4899@husc6.harvard.edu>
Reply-To: kaufman@polya.Stanford.EDU (Marc T. Kaufman)
Organization: Stanford University
Lines: 14

In article <4899@husc6.harvard.edu> olson@endor.UUCP (Eric K. Olson) writes:
>In a recent article Marc T. Kaufman writes:
->FYI: I have uncovered a bug in Quickdraw that can trash memory.
->Environment:  8-bit pixel, rowbytes > 4000 (e.g. 6000).  Draw a line from

>I believe that rowBytes must be less than 4096, and that the high-order
>bits are used as flags.

rowBytes must be <= 8190.  The high order 3 bits are flags.  See my earlier
posting about rowbytes > 8190.  'lsr'@apple says that a new version of the
PixMap will have a longint for rowBytes (but where will they put it?).  This
is needed because in 32-bit color mode 8190 bytes is only 2047 pixels per row.

Marc Kaufman (kaufman@polya.stanford.edu)