archive/{zzip,iso9660}: ignore file names which are invalid UTF-8

These malformed strings must not be transferred over the wire, because
the MPD protocol is defined to be UTF-8.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1274

src/archive/plugins/Iso9660ArchivePlugin.cxx

@@ -29,6 +29,7 @@
 #include "fs/Path.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/StringCompare.hxx"
+#include "util/UTF8.hxx"
 #include "util/WritableBuffer.hxx"
 
 #include <cdio/iso9660.h>
@@ -102,6 +103,10 @@ Iso9660ArchiveFile::Visit(char *path, size_t length, size_t capacity,
 			/* skip special names like "." and ".." */
 			continue;
 
+		if (!ValidateUTF8(filename))
+			/* ignore file names which are not valid UTF-8 */
+			continue;
+
 		size_t filename_length = strlen(filename);
 		if (length + filename_length + 1 >= capacity)
 			/* file name is too long */