File downloaded from Usenet fails hash check on first missing piece

[Iliek]

Here's something I've been wondering about for a while:

When downloading files from Usenet, it often happens that one will be missing one or more pieces and the available .par set cannot rebuild it. While the file downloaded will contain all data except for the missing pieces, if you find a .torrent for the exact same file and attempt to resume with the one you downloaded from Usenet, the hash check will always stop at the first missing piece.

I realize this is the way in which hash checking works and is expected behavior, but I wonder if any body knows of a way to utilize ALL the data possible from such a file. It seems possible to me that a program could exist which would be able to do this in a way such as padding the missing pieces using the .par.

Thank you for your consideration! Any insight would be much appreciated.

[DreadWingKnight]

If the missing pieces cause offset changes, this is unavoidable. If the missing pieces do not cause offset changes (such as when the pieces are only corrupt, and not the wrong size) then any and all complete pieces will be used to resume.