From 6972a9f945b57851178a014ae4382d229bf5ab8b Mon Sep 17 00:00:00 2001
From: Bryan Jurish <moocow.bovine@gmail.com>
Date: Fri, 20 Dec 2024 16:36:34 +0100
Subject: [PATCH] fix 'Runtime error: Tried to convert(null)' when multiplying
 all-missing CCS::Nd

---
 CCS/Nd.pm         |  6 +++---
 CCS/t/06_matops.t |  5 +++++
 testme.perl       | 17 ++++++++++++++++-
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/CCS/Nd.pm b/CCS/Nd.pm
index cf877c4..7555a57 100644
--- a/CCS/Nd.pm
+++ b/CCS/Nd.pm
@@ -164,7 +164,7 @@ sub fromWhich :lvalue {
   if (!$opts{steal}) {
     ##-- not stolen: copy or sever
     if (!$opts{sorted}) {
-      my $wi   = $wnd->isempty ? PDL->null->ccs_indx() : $wnd->vv_qsortveci;
+      my $wi   = $wnd->qsortveci;
       $wnd     = $wnd->dice_axis(1,$wi);
       $nzvals  = $nzvals->index($wi);
     }
@@ -1407,7 +1407,7 @@ sub _ccsnd_binary_op_mia {
       $avalsr = $avals;
     } else {
       $ixar          = $ixa->dice_axis(0,$ra);
-      my $ixar_sorti = $ixar->isempty ? PDL->null->ccs_indx() : $ixar->vv_qsortveci;
+      my $ixar_sorti = $ixar->qsortveci;
       $ixa           = $ixa->dice_axis(1,$ixar_sorti);
       $ixar          = $ixar->dice_axis(1,$ixar_sorti);
       $avalsr        = $avals->index($ixar_sorti);
@@ -1428,7 +1428,7 @@ sub _ccsnd_binary_op_mia {
       $bvalsr = $bvals;
     } else {
       $ixbr          = $ixb->dice_axis(0,$rb);
-      my $ixbr_sorti = $ixbr->isempty ? PDL->null->ccs_indx() : $ixbr->vv_qsortveci;
+      my $ixbr_sorti = $ixbr->qsortveci;
       $ixb           = $ixb->dice_axis(1,$ixbr_sorti);
       $ixbr          = $ixbr->dice_axis(1,$ixbr_sorti);
       $bvalsr        = $bvals->index($ixbr_sorti);
diff --git a/CCS/t/06_matops.t b/CCS/t/06_matops.t
index 2e88d0d..472be7d 100644
--- a/CCS/t/06_matops.t
+++ b/CCS/t/06_matops.t
@@ -245,5 +245,10 @@ my $m = identity(3)->set(2,2,0);  # [[1,0,0],[0,1,0],[0,0,0]]
 my $v = zeroes(1,3)->set(0,2,1);  # [[0],[0],[1]]
 pdlok('matmult with empty row', ($m->toccs x $v)->decode, ($m x $v));
 
+##-- no more type conversion support for null PDLs -- https://github.com/moocow-the-bovine/PDL-CCS/issues/14#issuecomment-2556862635
+my $u = zeroes(1, 3);
+my $z = ones(1, 3);
+pdlok('u*z all missing', ($u->toccs * $z->toccs)->decode, ($u * $z));
+pdlok('z*u all missing', ($z->toccs * $u->toccs)->decode, ($z * $u));
 
 done_testing;
diff --git a/testme.perl b/testme.perl
index 3fe017a..62b7eb5 100755
--- a/testme.perl
+++ b/testme.perl
@@ -922,7 +922,22 @@ sub test_matmult_gh14 {
 
   print STDERR "what now?\n"
 }
-test_matmult_gh14();
+#test_matmult_gh14();
+
+##---------------------------------------------------------------------
+## test_matmult_gh14
+##   + debug https://github.com/moocow-the-bovine/PDL-CCS/issues/14#issuecomment-2556862635
+sub test_matmult_gh14b {
+  my $u = zeroes(1, 3);
+  my $v = ones(1, 3);
+
+  my ($uc, $vc) = ($u->toccs, $v->toccs);
+  my $uvc = $uc * $vc; # Tried to convert(null) at /usr/lib/x86_64-linux-gnu/perl5/5.36/PDL/Core.pm line 2722.
+  pdlok('empty mult', $uvc->decode, ($u * $v));
+
+  print STDERR "what now?\n"
+}
+test_matmult_gh14b();
 
 ##---------------------------------------------------------------------
 ## DUMMY