Adding a warning On subscription deletion for item

If we really wanted to delete all items linked to a subscription when we delete a subscription
we should change the database structure as such :
ALTER TABLE serialitems ADD FOREIGN KEY ( itemnumber ) REFERENCES items (itemnumber) ON DELETE CASCADE ;
ALTER TABLE serial CHANGE subscriptionid subscriptionid INT( 11 ) NOT NULL
ALTER TABLE serial ADD INDEX subscription ( subscriptionid )
ALTER TABLE serial ADD FOREIGN KEY ( subscriptionid ) REFERENCES subscription (subscriptionid) ON DELETE CASCADE ;

C4/Serials.pm

@@ -2237,6 +2237,32 @@ sub CountIssues {
     return $countreceived;
 }
 
+=head2 HasItems
+
+=over 4
+
+$result = &HasItems($subscriptionid)
+
+
+=back
+
+=cut
+
+sub HasItems {
+    my ($subscriptionid) = @_;
+    my $dbh              = C4::Context->dbh;
+    my $query = qq|
+            SELECT COUNT(serialitems.itemnumber)
+            FROM   serial 
+			LEFT JOIN serialitems USING(serialid)
+            WHERE  subscriptionid=? AND serialitems.serialid NOT NULL
+        |;
+    my $sth=$dbh->prepare($query);
+    $sth->execute($subscriptionid);
+    my ($countitems)=$sth->fetchrow;
+    return $countitems;  
+}
+
 =head2 abouttoexpire
 
 =over 4

serials/subscription-detail.pl

@@ -56,10 +56,12 @@ if ($op eq 'del') {
     # Asking for confirmation if the subscription has not strictly expired yet or if it has linked issues
     my $strictlyexpired = HasSubscriptionStrictlyExpired($subscriptionid);
     my $linkedissues = CountIssues($subscriptionid);
-    if ($strictlyexpired == 0 || $linkedissues > 0) {
+    my $countitems   = HasItems($subscriptionid);
+    if ($strictlyexpired == 0 || $linkedissues > 0 || $countitems>0) {
 		$template->param(NEEDSCONFIRMATION => 1);
 		if ($strictlyexpired == 0) { $template->param("NOTEXPIRED" => 1); }
 		if ($linkedissues     > 0) { $template->param("LINKEDISSUES" => 1); }
+		if ($countitems       > 0) { $template->param("LINKEDITEMS"  => 1); }
     } else {
 		$issueconfirmed = "1";
     }