Sequential order not working after changing priority

[am01533nk0]

qBittorrent & operating system versions

qBittorrent: 4.3.9 x64
Operating system: Windows 11 21H2 10.0.22000
Qt: 5.15.2
libtorrent-rasterbar: 1.2.14

What is the problem?

Download in sequential order not working after changing priority, if priority not touched - it working (as investigation of progress bar)

Steps to reproduce

No response

Additional context

No response

Log(s) & preferences file(s)

No response

[nev3rfail]

Can confirm.
This behavior is present for the last few years at least.

More info on the bug:

Steps to reproduce:

1. Add new torrent to qBt
2. Enable "Download in sequential order" option for the new download
   2.1. Switch to "General" tab and watch files downloading sequentially, as intended
3. Change priority of one or multiple files in the download
4. Switch to "General" tab and watch random parts downloading, as like "Download in sequential order" option is not set

Additional information

If priority is set back to normal again, download then works as intended.

[glassez]

@arvidn, have you something to comment it?

[arvidn]

if any pieces are marked as time-critical, with set_piece_deadline(), those pieces will be prioritized. I assume that's not the case here though.

There's a picker_log_alert that contains hints on which mode the piece picker is used in, for every invocation of it (so, it's quite verbose). The alert_category::picker_log flag has to be set in the alert_mask.

When in sequential download mode, pieces with priority 0 are still requested. Perhaps because of this, qbt disables sequential mode whenever file priorities are changed.

[Rubber-Duckie]

Possibly linked #20849