Persist additional trackers and load it on startup

[vafada]

Closes #23508.

As suggested in #23510 (comment)

Save a copy of the tracker list file downloaded when Automatically append trackers from URL to new downloads is enabled.

Load the downloaded copy on startup (before calling prepareStartup) so if a torrent was in the CLI param and the --skip-dialog=true, the newly added torrent will have all the additional trackers in the list.

[vafada]

Questions:

• Do we need to delete the additional_trackers.txt if the Automatically append trackers from URL to new downloads option was unchecked?
• Do we need to re-download the file on startup if the additional_trackers.txt exists? Maybe download it only when additional_trackers.txt doesn't exists (previous version of qBittorrent)

qBittorrent/src/base/bittorrent/sessionimpl.cpp

Lines 685 to 689 in ae7cc74

	if (isAddTrackersFromURLEnabled())
	{
	updateTrackersFromURL();
	m_updateTrackersFromURLTimer->start();
	}

[glassez]

• Do we need to re-download the file on startup if the additional_trackers.txt exists?

I would follow the regular update interval.

• Do we need to delete the additional_trackers.txt if the Automatically append trackers from URL to new downloads option was unchecked?

I would delete it.

[stalkerok]

I think it makes sense to rename to additional_trackers_from_url.txt

[vafada]

I think it makes sense to rename to additional_trackers_from_url.txt

done in 90b3ae3

[glassez]

The following code is enough self-descriptive so this comment is redundant.

Suggested change

// if AddTrackersFromURLEnabled is enabled, load trackers from "additional_trackers_from_url.txt"

[glassez]

The following code is enough self-descriptive so this comment is redundant.

Suggested change

// if AddTrackersFromURLEnabled is enabled, redownload the file

[glassez]

Suggested change

	LogMsg(tr("Failed to load additional_trackers_from_url.txt. %1").arg(readResult.error().message), Log::WARNING);
	LogMsg(tr("Failed to load additional trackers from file. Reason: %1").arg(readResult.error().message), Log::WARNING);

[glassez]

Do we need to re-download the file on startup if the additional_trackers.txt exists?

I would follow the regular update interval.

I meant something more advanced than you did. But I'm not insisting.