Brian Stevens wrote:

> Joe Lertola wrote:
>>
>> I am guessing that the problem is caused by saving a resource too  
>> many times. The crash happens after calling USR ReplaceResource  
>> about 250 times. I have not been able to isolate where the crash  
>> happens with def.debugstring commands. But the crash usually seems  
>> to happen shortly after this line:
> The text in the reference manual for Def ChangedResource is  
> somewhat illuminating (USR ReplaceResource calls this). USR  
> ReplaceResource copies the handle.  Also, (just skimming) the USR  
> code does not call CloseResFile or UpdateResFile (CloseResFile  
> calls update first, so it is unnecessary in that case)  but just  
> marks it as changed with the DEF ChangedResource calls.  The  
> CloseResFile call releases the memory for the resource handles, so  
> maybe the app accumulates too many and finally crashes. Doing 250  
> CloseResFiles is not my recommendation  but strategically placed  
> might improve matters.   The old resource manager calls  probably  
> haven't changed from OS X 10.3 to 10.4, so the difference from one  
> machine to another is probably related to more or less memory being  
> available and not the OS version per se. 250 USR ReplaceResource  
> calls sounds excessive to me. I'd find a way to reduce this  
> regardless because your users will probably manipulate images  
> larger than those used in testing and the crash will come earlier.

In OS X 10.4, a resource tends to become corrupted if more than 16 MB  
of changes are made without a call to UpdateResFile. I don't know if  
this limit is different in 10.3, or how it relates to your 250 calls  
(16 MB/250 ≈ 64 K).

Immediately after your call
    pictHndl& = USR ReplaceResource( pictHndl&, _"PICT",  
_prevIconTemp, "tempIcon", gExternalGradientResource)
add this line
    UpdateResFile( gExternalGradientResource )
to see if it repairs the problem.

Robert P.