Different workaround for mysterious taint issues under perl 5.20

Bugzilla/Component.pm

@@ -39,7 +39,7 @@ use constant NAME_FIELD => 'name';
 
 use constant LIST_ORDER => 'product_id, name';
 
-use constant DB_COLUMNS => qw(
+sub DB_COLUMNS() { qw(
     id
     name
     product_id
@@ -48,7 +48,7 @@ use constant DB_COLUMNS => qw(
     description
     wiki_url
     isactive
-);
+) }
 
 use constant REQUIRED_CREATE_FIELDS => qw(
     name

Bugzilla/Product.pm

@@ -47,7 +47,10 @@ use constant FIELD_NAME => 'product';
 use constant NAME_FIELD => 'name';
 use constant LIST_ORDER => 'name';
 
-use constant DB_COLUMNS => qw(
+# Workaround mysterious taint issue:
+# join('', DB_COLUMNS) will be tainted if defined as 'use constant'
+# (although none of the columns themselves will be tainted in that case)
+sub DB_COLUMNS() { qw(
     id
     name
     wiki_url
@@ -62,7 +65,7 @@ use constant DB_COLUMNS => qw(
     allows_unconfirmed
     cc_group
     entryheaderhtml
-);
+) }
 
 use constant REQUIRED_CREATE_FIELDS => qw(
     name

editproducts.cgi

@@ -376,6 +376,7 @@ if ($action eq 'updategroupcontrols')
         {
             my $count_id = $1;
             my $id = $ARGS->{$f};
+            next if !$id;
             trick_taint($id);
             if ($ARGS->{"membercontrol_$count_id"} == CONTROLMAPNA)
             {