Do not croak when receiving invalid XML

lib/Travel/Status/DE/HAFAS.pm

@@ -180,9 +180,15 @@ sub new {
 	# errors in delay="...") when setting the language to dutch/italian.
 	# No, I don't know why.
 
-	$ref->{tree} = XML::LibXML->load_xml(
-		string => $ref->{raw_xml},
-	);
+	eval { $ref->{tree} = XML::LibXML->load_xml( string => $ref->{raw_xml} ) };
+
+	if ( my $err = $@ ) {
+		if ( $ref->{developer_mode} ) {
+			say $ref->{raw_xml};
+		}
+		$ref->{errstr} = "Backend returned invalid XML: $err";
+		return $ref;
+	}
 
 	if ( $ref->{developer_mode} ) {
 		say $ref->{tree}->toString(1);

t/30-invalid-xml.t

@@ -6,7 +6,7 @@ use 5.020;
 use utf8;
 
 use File::Slurp qw(read_file);
-use Test::More tests => 1;
+use Test::More tests => 2;
 
 use Travel::Status::DE::HAFAS;
 
@@ -15,7 +15,18 @@ my $xml = 'lol';
 my $status = Travel::Status::DE::HAFAS->new(
 	service => 'DB',
 	station => 'Berlin Jannowitzbrücke',
-	xml => $xml
+	xml     => $xml
 );
 
-is (scalar $status->results, 0, 'no results on invalid input');
+is( scalar $status->results,
+	0, 'no results on valid XML with invalid HAFAS data' );
+
+$xml = 'lol<';
+
+$status = Travel::Status::DE::HAFAS->new(
+	service => 'DB',
+	station => 'Berlin Jannowitzbrücke',
+	xml     => $xml
+);
+
+is( scalar $status->results, 0, 'no results on invalid XML' );