Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site utcs.uucp
Path: utzoo!utcs!wjr
From: wjr@utcs.uucp (William Rucklidge)
Newsgroups: net.micro.amiga
Subject: Re: FreeDiskObject
Message-ID: <1163@utcs.uucp>
Date: Wed, 19-Mar-86 18:07:51 EST
Article-I.D.: utcs.1163
Posted: Wed Mar 19 18:07:51 1986
Date-Received: Wed, 19-Mar-86 18:23:21 EST
References: <1538@gitpyr.UUCP>
Reply-To: wjr@utcs.UUCP (William Rucklidge)
Organization: University of Toronto Computing Services, general purpose UNIX
Lines: 50
Summary: 

In article <1538@gitpyr.UUCP> wutka@gitpyr.UUCP (Mark Wutka) writes:
>   I don't know if anyone else has had trouble getting Amiga Hack to work
> but I have...actually, the only problem I have had is in the save command.
> When I tried to save a game it hung...I traced the problem all the way
> down to the FreeDiskObject call in makeicon. Is there something wrong
> with this routine ??
> Mark Wutka
> ...!{akgua,allegra,amd,hplabs,ihnp4,masscomp,ut-ngp}!gatech!gitpyr!wutka
> ...!{rlgvax,sb1,uf-cgrl,unmvax,ut-sally}!gatech!gitpyr!wutka


Well, there is nothing wrong with this routine, but there are a couple of
problems with the code around it: the routine is
makeicon, in hack.icon.c (in part 10 of the posting). The original code
reads:

	if ( (object = GetDiskObject(source)) == NULL)
		myprintf("Cannot get source icon - err #%d\n", IoErr() );
	object->do_CurrentX = NO_ICON_POSITION;
	object->do_CurrentY = NO_ICON_POSITION;
	if ( (object = PutDiskObject( name, object )) == NULL)
		myprintf("Cannot create save icon - err #%d\n", IoErr() );
	FreeDiskObject(object);

which I have modified to read:

   if ( (object = GetDiskObject(source)) == NULL) {
      myprintf("Cannot get source icon - err #%d\n", IoErr() );
   } else {
      object->do_CurrentX = NO_ICON_POSITION;
      object->do_CurrentY = NO_ICON_POSITION;
      if ( (PutDiskObject( name, object )) == NULL)
         myprintf("Cannot create save icon - err #%d\n", IoErr() );
      FreeDiskObject(object);
      }

which seems to work fine, whether the icons exist or not.
The problem is that the routine PutDiskObject was returning a status, which
was overwriting the pointer to the object. Later, freeing that pointer
caused the crash.

My copy of hack still has a problem, though - attempting to wield bare hands
causes a Task Held error... I haven't been able to figure this one out yet.
Oh well...

-- 
William Rucklidge	University of Toronto Computing Services
{decvax,ihnp4,utcsri,{allegra,linus}!utzoo}!utcs!wjr
GISO - Garbage In, Serendipity Out.
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