#398 $pdl->hdr items are lost after $pdl->reshape

[kmx]

my $x = ones(25);
$x->hdr->{demo} = "yes";
say $x->info; # PDL: Double D [25]
say $x->sum; # 25
say $x->hdr->{demo} ? "exists" : "NOT FOUND"; # here it's OK

$x->reshape(5,5);
say $x->info; # PDL: Double D [5,5]
say $x->sum; # 25
say $x->hdr->{demo} ? "exists" : "NOT FOUND"; ### item does not exist!!!!!

[Chris Marshall]

It appears that reshape() makes pdl of the input argument with pdl(). If this is replaced by PDL::Core::topdl() instead then the hdr appears to be preserved. pdl() makes a copy which is where the hdr is dropped.

sub PDL::reshape{
if (@ == 2 && $[1] == -1) { # a slicing reshape that drops 1-dims
return $[0]->slice( map { $==1 ? [0,0,0] : [] } $[0]->dims);
}
my $pdl = pdl($[0]);
my $nelem = $pdl->nelem;
my @dims = grep defined, @[1..$#_];
for my $dim(@dims) { barf "reshape: invalid dim size '$dim'" if $dim < 0 }
@dims = grep($ != 1, $pdl->dims) if @dims == 0; # get rid of dims of size 1
$pdl->setdims([@dims]);
$pdl->upd_data;
if ($pdl->nelem > $nelem) {
my $tmp=$pdl->clump(-1)->slice("$nelem:-1");
$tmp .= 0;
}
$_[0] = $pdl;
return $pdl;
}

[kmx]

I have pushed the fix you have proposed to branch kmx-fix-for-SF#398

[Chris Marshall]

Fixed in git master and will appear in next CPAN release.