fix Slices::indexND with an empty used as an lvalue - fix #535

Author: mohawk2

Changes

@@ -4,6 +4,7 @@
 - {and,or}over output type now same as input type (#533)
 - add Ufunc::{b,}xorover (#533) - thanks @jo-37
 - fix Math::polyroots crashing on [2 1 0 1] (#536) - thanks @pipatron for report
+- fix Slices::indexND with an empty used as an lvalue (#535) - thanks @yelnats for report
 
 2.099 2025-01-23
 - fix test that assumed acosh(0)->byte, i.e. nan()->byte, was always 0 (#514) - thanks @eserte for report

lib/PDL/Core.xs

@@ -872,7 +872,7 @@ BOOT:
   /* modified from https://www.perlmonks.org/?node_id=849145 */
   char *package = "PDL";
   HV* stash = gv_stashpvn(package, strlen(package), TRUE);
-  char *meths[] = { "sever", NULL }, **methsptr = meths;
+  char *meths[] = { "sever", "new_from_specification", NULL }, **methsptr = meths;
   for (; *methsptr; methsptr++) {
     SV **meth = hv_fetch(stash, *methsptr, strlen(*methsptr), 0);
     if (!meth) croak("No found method '%s' in '%s'", *methsptr, package);

t/lvalue.t

@@ -10,6 +10,7 @@ my @lv_subs = map [$_], qw(
   dice flat indexND indexNDb broadcast nslice_if_pdl px range reorder reshape
   sever slice indexNDb mslice
 );
+push @lv_subs, map [$_, zeroes(indx,2,0)], qw(indexND);
 push @lv_subs, map [$_, 1], qw(clump dummy index unbroadcast);
 push @lv_subs, map [$_, pdl 1], qw(where whereND);
 push @lv_subs, map [$_, 0, 1], qw(diagonal);