So I have the following code which has been working find under Perl 
5.6 for a number of years:

    tie my %stateinfo, 'CrunchHash';
    foreach my $field (keys %$TransformedStateHash) {
       my $alias = $WatcherAliasFromField{$field};
       $stateinfo{$alias} = [$TransformedStateHash-> {$field}, undef];
       $stateinfo{$field} = [$TransformedStateHash-> {$field}, undef];
    }

So what happens here is that "sometimes" $alias comes back as undef 
(this is true under both Perl 5.6 and 5.8).

Under Perl 5.6 that is okay . . . because $stateinfo is a tied hash 
and the STORE routine checks the "key" and finds it as "undef" and so 
it just NOPs the store . . . that is it just does a "return" in the 
STORE routine without trying to save anything in the underlying hash.

Under Perl 5.8, it looks like what is happening is that the check for 
undef is done by Perl BEFORE calling STORE . . . as a result it 
throws a warning which is not desired.

I mean I could fix the code with a simple "if defined($asia)" at the end.

My concerns are:

1. The if-defined solution, while easy might, there might be are 
other situations like this, perhaps a lot of them that are also going 
to be an issue.  I'd rather not go find/touch all of them.

2. It seems to me that Perl needs to check the key INSIDE STORE . . . 
not before the call is made.  God only know what STORE might do to 
"key" before actually inserting it into the underlying hash.  So 
while my analysis here seem reasonable on the surface, it really 
doesn't make sense given the language construct.

3. Since there is no mention of something like this in the Porting 
documents, (at least that I could directly related to this), I'm 
wondering if I am dealing with the real problem, or something more 
subtle in disguise.

Comments welcomed.

Frank