Comment 4 for bug 1599539

The original issue turned out to be trivial. The dot and dot-dot entries need to be the two very first entries in a non-root directory table; however, readdir() does not guarantee that "." and ".." will be the first items returned. When I patched read_directory() to generate "." and ".." entries first (and also ensured that volume label entry is generated with zero size), ScanDisk stopped complaining.

The latter issue is also easy. The FAT16 file system cannot hold more than 512 entries in its root directory table. The vvfat driver does not recognise this limit and tries to squeeze more entries into the table than is normally possible. FAT-reading software doesn't seem to appreciate it. The driver should emit a warning and refuse to generate a FAT image altogether. (I have actually thought of a way to do it anyway, but it will not work everywhere.)