On Nov 14, 2007, at 2:25 PM, Lake Group wrote:

>  Should we be changing IsHandleValid everywhere?
Not necessarily everywhere. Keep in mind we are bypassing an Apple  
bug. Hopefully, at some point it will be fixed. The primary place to  
fix is the runtime appearance include(as covered by Robert P earlier)  
because that impacts every program compiled with the appearance runtime.




> Using MyIsHandleValid in the situation below (from DataBrowser for  
> Dummies) causes a crash.
I'm sure Alain would agree that some of this code needs review  
especially in light of OS X. For example, handle locks are not really  
necessary in OS X.

Also, this code snippet begs more questions that could only be  
answered by looking at the code that calls this fn.  Array is defined  
as a pointer to long in the argument list. Presumably, the long is a  
handle (if so, it should be defined as one). Dereferencing array  
(array.nil&) and passing it to IsHandleValid looks suspect, but again  
without looking at the calling code....



> Assuming there's pointer/handle situation here.  There are 9 or 10  
> fn's in the DB for Dummies that pass  array.nil&. Perhaps there are  
> others of this nature scattered about?
Maybe. Again, this code needs a review not only for a substitute for  
IsHandleValid, but also for other methods.

Your code might need to be adapted to use Robert's substitute for  
IsHandleValid. For example, the pointer to a long type  in Fn  
BrowserAddItems does not match the handle type defined in Robert's  
function. The point is to bypass IsHandleValid for now. This effort  
will probably require some thinking and study to get all code working.



>
> Also, Drag and Drop is out in all my FB apps. (Used code from FB  
> sample code.)
By "out", I assume this means D&D is not working?  Unfortunately,  
this is not enough information to help you. BTW: FB sample code  
should not be relied upon to be flawless. Some of that code is stale  
and needs updating.


Brian S.