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From: lsr@apple.UUCP
Newsgroups: net.micro.mac
Subject: OpenResFile behavior
Message-ID: <143@apple.UUCP>
Date: Thu, 21-Aug-86 19:26:44 EDT
Article-I.D.: apple.143
Posted: Thu Aug 21 19:26:44 1986
Date-Received: Sat, 23-Aug-86 22:02:34 EDT
Organization: Advanced Development Group, Apple Computer
Lines: 21
Keywords: OpenResFile, bug

Recently there was a message concerning funny behavior in OpenResFile.  I
lost the original message, but the answer is described in Tech Note #78.

On the 64K ROM, there was a patch to OpenResFile that checks to see if the
string being passed is the name of a printer, by inspecting the high bits of
the pointer to the file name.  If the high bits indicate a resource, then
the patch will call RecoverHandle on the alleged handle, which will crash if
the pointer is not to a resource..

The fix is to mask off the high-order byte of the address you pass to
OpenResFile, to ensure that it is not flagged as a resource.

-- 
Larry Rosenstein

Object Specialist
Apple Computer

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