Avoiding Query Bug in GetExtraIcons Call

One of the Newton 2.x OS Q&As
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This document was exported on 7/23/97.

Avoiding Query Bug in GetExtraIcons Call (8/2/96)

Q: Some calls to GetExtraIcons result in an undefined Query method exception. How can I fix this?

A: There is a bug in the implementation of GetExtraIcons. The code is not checking if the store has any extras information on it, so the Query message is getting sent to a NIL soup. The result is the exception.

At this time it is not clear if or when this bug will be fixed. I suggest you use the following workaround code when you call GetExtraIcons:

    try
        GetExtraIcons(...)
        // do whatever you need to do here
        
    onexception |evt.ex.fr.intrp;type.ref.frame| do
    begin
        // check for a problem calling the Query function
        if currentException().data.errorCode = -48809 AND
                currentException().data.symbol = 'Query then
        begin
            // no extras drawer info on the store
        end ;
        else
            // a real error has occured, so let system handle it
            ReThrow() ;
    end ;