Bug 23463: (follow-up) Fix timestamp default value

For discussion, this patch revert the changes made previously.

This line exists in Koha::Item->store as it is the translation of:
    if (exists $item->{'timestamp'}) {
        delete $item->{'timestamp'};
    }
that was coming from _do_column_fixes_for_mod (called from ModItem)

To preserve existing behavior I would be in favor of keeping it like that to
avoid regression, and deal with it separately if we want to improve/remove it.

So basically here we are setting it to undef in Koha::Item->store to make it
handle correctly by the parent Koha::Object->store. I agree that's kind of weird
and must be improved.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Koha/Item.pm

@@ -148,9 +148,7 @@ sub store {
             $self->permanent_location( $self->location );
         }
 
-        if ( $self->timestamp ) {
-            $self->timestamp(dt_from_string); # Maybe move this to Koha::Object->store?
-        }
+        $self->timestamp(undef) if $self->timestamp; # Maybe move this to Koha::Object->store?
 
         C4::Biblio::ModZebra( $self->biblionumber, "specialUpdate", "biblioserver" );
 

Koha/Object.pm

@@ -151,6 +151,12 @@ sub store {
                     $self->_result()->set_column($col => $columns_info->{$col}->{default_value});
                 }
             }
+            elsif ( not defined $self->$col
+                  && $columns_info->{$col}->{datetime_undef_if_invalid} )
+              {
+                  # timestamp
+                  $self->$col( $columns_info->{$col}->{default_value} );
+              }
         }
     }