Extend t/13disconnect.t test for localizing HandleError

Add test case that custom HandleError and also localized custom HandleError
does not trigger any error after disconnect.

t/13disconnect.t

@@ -10,11 +10,21 @@ require 'lib.pl';
 
 my $dbh1 = DbiTestConnect($test_dsn, $test_user, $test_password, { RaiseError => 1, PrintError => 0 });
 
-plan tests => 17;
-
+plan tests => 19;
+
+my $err1;
+my $err2;
+# set HandleError with catching of all errors
+$dbh1->{HandleError} = sub { $err1 = $_[0]; };
+{
+# localize HandleError with different closure and ensure that the original one is restored after the disconnect()
+local $dbh1->{HandleError} = sub { $err2 = $_[0]; };
 ok $dbh1->{Active};
 ok $dbh1->disconnect();
 ok !$dbh1->{Active};
+}
+ok !defined $err1 or diag $err1;
+ok !defined $err2 or diag $err2;
 
 ok my $dbh2 = DBI->connect($test_dsn, $test_user, $test_password, { RaiseError => 1, PrintError => 0 });
 ok my $dbh3 = DBI->connect($test_dsn, $test_user, $test_password, { RaiseError => 1, PrintError => 0 });