#libtorrent

RC_1_2: Crashes when checking torrent(s) with piece size of 256.0 MiB

arvidn on Sep 29, 2024

(...) However, I also think an important consideration is whether it ever makes sense to have piece sizes this large. It adds friction to sharing data. You have to download more bytes before you can start upload them.

So you're releasing a version of the software that breaks hundreds of thousands of existing torrents, without an error message explaining 1) what's happening and 2) that the problem can be evaded by downgrading...? Why is this a "stable" release?

The dev credited for the qBittorrent "bugfix" wasn't happy with it:

Disable the ability to create torrents with a piece size of 256MiB

stalkerok commented on Sep 21, 2024:

1. It doesn't make much sense to only prevent the creation of such torrents without preventing such torrents from being added to session.

In any case, users are already using torrents with a 256MiB piece size for lt1.2 and won't be happy with that. (...)

But these restrictive measures still won't fix the issue for lt1.2...

stalkerok commented on Sep 21, 2024

As I said, it can be used as a temporary solution for 5.0, which won't break anything for sure. Anyway, I don't have the skills to make something bigger.

(People mostly only started reporting that their torrents were breaking or silently vanishing in 5.0.1+ (examples: 1, 2), so I guess it didn't actually break anything.)

stalkerok commented on Oct 3, 2024

As far as I understand this PR is no longer relevant since a fix has been submitted to libtorrent, what if I make it possible to create 256MiB torrents for lt1.2 as well?

Apparently not:

xavier2k6 commented on Oct 4, 2024:

Have tested, latest libtorrent RC_1_2 commit now rejects loading & removes any previous torrent with a invalid piece size of 256MiB.

RC_2_0 is now on par with RC_1_2 with the torrent creation limit of 128MiB piece size.

However, RC_2_0 needs to have a patch rejecting the invalid piece size torrents as it still allows adding new torrents of 256MiB piece size/loading previously added to session......