[mapserver-users] Re: Perl/mapscript error

[Giorgio Volpe]

Puneet Kishor wrote:
> 
> ok... I have spent a good part of today battling this, and have
> discovered the following...
> 
> one of the reasons I am getting these errors because I have -w switch on
> my shebang line. After much finagling, I can get the image to draw, but
> with the -w switch I get the following error as well --
> 
> (in cleanup) Not a HASH reference at /Library/Perl/darwin/mapscript.pm
> line 1468.
> 
> that line in mapscript.pm is the one that is trying to clean up... and
> failing. Specifically,
> 
> sub DESTROY {
>      my $self = tied(%{$_[0]});
>      delete $ITERATORS{$self};
>      if (exists $OWNER{$self}) {
>          mapscriptc::delete_mapObj($self);
>          delete $OWNER{$self};
>      }
> }

I've the same problem!
It is not a warning but a fatal error for perl.

The problem, i guess, is related to the use of tied hash to support
mapscript objects ... 

I've added a PRINT ...

sub DESTROY {
    print STDERR "!!!! Destroing $_[0] ...\n";
    my $self = tied(%{$_[0]});
    ...

The DESTRUCTOR is called two times! The first one with $_[0] that is a
reference to an hash, the second to a scalar so function "tied" raises
the error!

!!!! Destroing layerObj=HASH(0x83e925c) ...
!!!! Destroing layerObj=SCALAR(0x83d8ef4) ...

Empirically i've seen that, if I undef the variable containing the
reference to the object before returning from the sub where i use it,
than the error disappears ... (also if the two call to the DESTRUCTOR
are always there, but probably the undef value is passed)


We need a PERL guru ...!

-- 

    Giorgio

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