RE: "Can't bless non-reference" error, bug or not?

Larry,

You are right. We shouldn't call the method twice.

Thanks a lot,
Chunyan Wei

-----Original Message-----
From: Larry Wall [mailto:[email protected]]
Sent: Monday, May 15, 2000 10:39 PM
To: [email protected]
Cc: '[email protected]'; Brian Jepson
Subject: Re: "Can't bless non-reference" error, bug or not?


Chunyan Wei writes:
: diff -c AutoLoader.pm AutoLoader.pm.fixed
: *** AutoLoader.pm       Tue Sep 14 21:13:19 1999
: --- AutoLoader.pm.fixed Tue Apr 18 13:57:22 2000
: ***************
: *** 225,231 ****
:           $METHOD = sub {
:               my $self = shift;
:             my $class = JNI::FindClass($jclassname);
: !             bless $class->JNI::NewObjectA($mid, \@_), $classname;
:           };
:       }
:       elsif (ref $_[0]) {
: --- 225,233 ----
:           $METHOD = sub {
:               my $self = shift;
:             my $class = JNI::FindClass($jclassname);
: !             if ( ref $class->JNI::NewObjectA($mid, \@_)) {
: !                bless $class->JNI::NewObjectA($mid, \@_), $classname;
: !             }
:           };
:       }
:       elsif (ref $_[0]) {
: ***************
: *** 234,244 ****
:                   my $self = shift;
:                   if (ref $self eq $classname) {
:                       my $callmethod = "JNI::Call${rettype}MethodA";
: !                     bless $self->$callmethod($mid, \@_), $blesspack;
:                   }
:                   else {
:                       my $callmethod =
: "JNI::CallNonvirtual${rettype}MethodA";
: !                     bless $self->$callmethod($class, $mid, \@_),
: $blesspack;
:                   }
:               };
:           }
: --- 236,250 ----
:                   my $self = shift;
:                   if (ref $self eq $classname) {
:                       my $callmethod = "JNI::Call${rettype}MethodA";
: !                     if ( ref $self->$callmethod($mid, \@_)) {
: !                        bless $self->$callmethod($mid, \@_),
: $blesspack;
: !                     }
:                   }
:                   else {
:                       my $callmethod =
: "JNI::CallNonvirtual${rettype}MethodA";
: !                     if ( ref $self->$callmethod($class, $mid, \@_)) {
: !                        bless $self->$callmethod($class, $mid, \@_),
: $blesspack;
: !                     }
:                   }
:               };
:           }
: ***************
: *** 261,267 ****
:           if ($blesspack) {
:               $METHOD = sub {
:                   my $self = shift;
: !                 bless $class->$callmethod($mid, \@_), $blesspack;
:               };
:           }
:           else {
: --- 267,275 ----
:           if ($blesspack) {
:               $METHOD = sub {
:                   my $self = shift;
: !                 if ( ref $class->$callmethod($mid, \@_)) {
: !                    bless $class->$callmethod($mid, \@_), $blesspack;
: !                 }
:               };
:           }
:           else {

Why do you call the method twice in each case?  It'd be much more
efficient to store the result of the first call in a temporary and just
bless that if it's a ref.  Worse than that, in some cases calling the
same method twice can produce totally incorrect results, if the method
has side effects.

Larry