BEP47 - padding files

[alanmcgovern]

Can the text of the BEP be clarified to explain what happens for the final non-empty file in a torrent. Logically no padding file is necessary as no alignment is needed. The BEP text currently states Padding files are synthetic files inserted into the file list to let the following file start at a piece boundary which further implies that padding files are only inserted when there is a subsequent non-empty file.

qbittorrent-hybrid.zip

EDIT: Specifically, I'm looking to get the text of the BEP updated to state that adding padding to the final file is an error.

However, as some torrent clients already (incorrectly?) create these padding files it should also encourage implementors to support this case.

[the8472]

EDIT: Specifically, I'm looking to get the text of the BEP updated to state that adding padding to the final file is an error.

They're not an error (something that would render a torrent unprocessable). They're perhaps unnecessary, but shouldn't pose a problem for clients.

In the end padding files are just a signalling mechanism retrofitted onto BEP3 to omit some zero-byte ranges introduced for alignment. You still have to be able to process a torrent as-if those padding files were just regular files in case you're talking to a peer that doesn't understand padding files and will request blocks in those byte-ranges for example.