I have submitted a bug report whose text I reproduce below. A file with
the code from below is attached to the bug report.
http://sourceforge.net/tracker/index.php?func=detail&aid=1164766&group_id=16572&atid=116572
Regards,
Rob.
Unhook() causes perl Warning
-------------------------------
This example shows a problem with Win32::GUI::UnHook()
method.
The UnHook call appears to be the cause of error messages:
Attempt to free unreferenced scalar: SV 0x1a5519c, Perl
interpreter: 0x15d40a4 at unhookBug.pl line 40.
From perldiag:
Attempt to free unreferenced scalar:
(W internal) Perl went to decrement the reference count of a
scalar to see if it would go to 0, and discovered that it had
already gone to 0 earlier, and should have been freed, and in
fact, probably was freed. This could indicate that
SvREFCNT_dec() was called too many times, or that
SvREFCNT_inc() was called too few times, or that the SV
was mortalized when it shouldn't have been, or that memory
has been corrupted.
Workaround:
It is possible to turn off internal warnings (that are on by
default) by setting no warnings (internal);
I'm certainly no XS expert, but it looks like it's possible to get
SvREFCNT_dec(*removedvalue) called twice in UnHook().
Is this the problem?
use strict;
use warnings;
#Turning off internal warnings removes the messages
#no warnings qw(internal);
use Win32::GUI 1.0;
my $WM_MOUSEMOVE = 512;
my $mw = new Win32::GUI::Window (
-size => [200,200],
);
$mw->Hook($WM_MOUSEMOVE, \&handler)
or die "Failed to add Hook";
$mw->UnHook($WM_MOUSEMOVE, \&handler)
or die "Failed to remove hook";
exit(0);
