Subject: "Mercutio MDEF" Bug
Date: Mon, 8 Dec 97 05:42:50 -0800
From: Jorg Brown <brown@connectix.com>
To: "Ric Ford"


Sorry to use your direct e-mail line, but something came up that I think 
was worth getting your direct attention.

There is a piece of software named the Mercutio MDEF, which allows Mac 
programmers to more easily customize the look and feel of their menus.  
The number of developers using it is quite extensive - here's a partial 
list:

Adobe FrameMaker, Adobe PageMaker, Adobe PageMill, Adobe Photoshop, Adobe
SiteMill, Alpha Text Editor, Apollo, BBEdit, CADintosh, CodeWarrior,
Communicate Lite 1.5, Curvus Pro, Digital Performer, Dot-to-Dot, FastPace
Instant Contact, Final Draft, Graf 4.0, Graphic Converter, GrunerTweig,
Hyperion, IN CONTROL, Idea Keeper, Imagexpo 2.0, Ircle 3.0, LanSatellite,
Lemur, LetterRip, Librarian, MRGraphics, MT-NewsWatcher, Mac JDK,
MacPerl, MacZPoint, Mulberry, Mulligan's Golf Personal, Netscape
Navigator, Newton's Aquarium, ObjectPlant, Openlab, PEAK digital audio
tools, PageStream, PatchDance v0.4.6, Programmable Calculator, Radio
Master, Screen Catcher, ScriptableAdmin, Style, Super Countdown,
WebCollage, netOctopus, Symantec C++, Roaster, Icon Medical Systems,
Claris E-mailer, Astound, NewsHopper, MacPerl, IPTech (for Apple Network
Server), Warlords II (SSG), Deck II from MacroMedia

The problem is, part of the Mercutio MDEF changes the state of some core 
graphics structures on the Mac.  Technically speaking, it unlocks the 
GDevices.  QuickDraw unfortunately depends on the state of these 
structures not changing, but the dependency is very subtle - most of the 
time what Mercutio does is not noticeable.  This is why it has taken so 
long to finger Mercutio as the cause.

When I was notified of this, I realized for the first time that the 
reason my Mac had been crashing approximately every 3 days or so was 
because of this bug (I was consistently crashing inside of a Toolbox 
routine named NQDStdText).  Although a solution is said to be in the 
works, I wrote up a quick fix, and I am including it in this message.  
Feel free to distribute it.

Jorg 'jbx' Brown
Really p.o'd, but glad to have a stable Mac again
Connectix Corp



Dec. 9, 1997 Update from Jorg Brown:


Version 1.0.1 of MercutioGuard fixes a problem that crashes 
Timbuktu to crash (it disables itself 
during Timbuktu). 

It "also includes a new icon and version resource, per 
request of Digital Alchemy." Digital Alchemy apparently claims that the 
bug only happens 
on multiple-monitor machines.