Metaflac: no output file when using -o and changes weren't needed

[Wallboy]

I use metaflac in a script that removes tags using --remove-all-tags-except= along with the -o option to output to a different path.

However, if a particular flac does not have any tags that need removing at all, then metaflac simply doesn't touch the file at all and exits. I would at least expect that it should copy the file to the specified output path.

Or at least have in the documentation this behavior.