Cannot add a download without a populated file list

[drew2a]

Describe the bug

Downloads do not appear on the Downloads page after clicking the "download" button.

To Reproduce

1. Run Tribler
2. Search for "ubuntu"
3. Press the download icon for a torrent with 0 or just a few seeders
4. Quickly hit the "Download" button before the file list has a chance to populate
5. Go to the Downloads Page

Expected behavior
I expect this download on the Downloads Page, but it is empty.

Desktop (please complete the following information):

• OS: macOS
• Tribler's version: main a25df64ad67e263fe84f65a0faa4753737bf914b
• Python: 3.9.6

[qstokkink]

Cannot reproduce on Ubuntu 20.04.6 LTS/Python 3.8.10/main (a25df64ad67e263fe84f65a0faa4753737bf914b).

[drew2a]

Update: If you wait until the file list appears and then press "Download", it works. If you press download immediately after the dialog shows, then the download is not added.

Aside from that, if you have one download and you stop Tribler and restart it, you will see:

I think these are two different bugs. I'll do a little investigation and update the issue.

[drew2a]

I guess it is easier to reproduce the bug if you choose a torrent with just a few seeders.

[drew2a]

Somewhy the new download went to this execution path:

[tribler-core PID:91107] 2023-12-11 12:58:40,060 - INFO - DownloadManager(549) - Start download from URI: magnet:?xt=urn:btih:b22ec09e5c45ad737f18010228c24f7acee4d3a6&dn=Ubuntu 16.10
[tribler-core PID:91107] 2023-12-11 12:58:40,060 - INFO - DownloadManager(557) - Magnet scheme detected
[tribler-core PID:91107] 2023-12-11 12:58:40,061 - INFO - DownloadManager(559) - Name: Ubuntu 16.10. Infohash: b'\xb2.\xc0\x9e\\E\xads\x7f\x18\x01\x02(\xc2Oz\xce\xe4\xd3\xa6'
[tribler-core PID:91107] 2023-12-11 12:58:40,061 - INFO - DownloadManager(566) - Metainfo not found in cache
[tribler-core PID:91107] 2023-12-11 12:58:40,062 - INFO - DownloadManager(577) - Starting download: filename: None, torrent def: <tribler.core.components.libtorrent.torrentdef.TorrentDefNoMetainfo object at 0x122605880>
[tribler-core PID:91107] 2023-12-11 12:58:40,062 - INFO - DownloadManager(595) - Infohash: b'\xb2.\xc0\x9e\\E\xads\x7f\x18\x01\x02(\xc2Oz\xce\xe4\xd3\xa6'. Download: Download <name: 'metainfo request' hops: 1 checkpoint_disabled: 1>
[tribler-core PID:91107] 2023-12-11 12:58:40,062 - INFO - DownloadManager(598) - Download exists and metainfo is not requested.

and ended up on this return:

tribler/src/tribler/core/components/libtorrent/download_manager/download_manager.py

Line 592 in a25df64

return download

The additional logging added here: #7769

[qstokkink]

I reproduced this yesterday. After clicking back and forth between the "All" and "Downloading" tabs, the download would appear. This may be a refresh issue.

[drew2a]

This behavior was introduced in

• Made TorrentDef.load async and threaded #7666

I've tested it with the following commits:

• d018d66. Works correctly.
• f610c82. Works incorrectly.

Related to (has a common root cause):

• Checkpoint information is shown on the Downloads Page just after Tribler is run #7770

[kozlovsky]

Fixed in #7939