Bug 490894

Summary:	KTorrent persistently writing 2 bytes to a "magnets" file while torrents are active
Product:	[Applications] ktorrent	Reporter:	Luke Horwell <code>
Component:	general	Assignee:	Joris Guisson <joris.guisson>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	NOR
Version First Reported In:	24.05.2
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:	https://invent.kde.org/network/ktorrent/-/commit/ebeaf20737bd9b02ac703e243ae2b9aef7ed32e0	Version Fixed/Implemented In:	25.08.1
Sentry Crash Report:

Description Luke Horwell 2024-07-27 16:15:50 UTC

SUMMARY

When a torrent is active, i.e. downloading or seeding, a file named "magnets" in ~/.local/share/ktorrent is persistently being written to in a loop. This causes the HDD activity indicator to be constantly flickering on/off.

The content of that file is just 2 bytes: "le". Happens even under a fresh configuration. No magnets are active.

STEPS TO REPRODUCE
1. Start a torrent, such as KDE Neon ISO.

STEPS TO DIAGNOSE
1. Install "inotifywait" package for the distro
2. Run "inotifywait -m -r /home/$USER/.local/share/ktorrent/"

WORKAROUND
Create a symbolic link for "magnets" to "/dev/null".

SOFTWARE/OS VERSIONS
OS: Arch Linux
KDE Plasma Version: 6.1.3
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2

ADDITIONAL INFORMATION
- Still happens even if all plugins are disabled.
- Deleting the file immediately recreates it.

Comment 1 Luke Horwell 2024-07-27 16:17:02 UTC

Forgot to add the output of inotifywait, if it helps:

```
/home/luke/.local/share/ktorrent/ OPEN magnets
/home/luke/.local/share/ktorrent/ MODIFY magnets
/home/luke/.local/share/ktorrent/ CLOSE_WRITE,CLOSE magnets
```
(repeated multiple times every second)

Comment 2 Bug Janitor Service 2025-06-28 18:11:50 UTC

A possibly relevant merge request was started @ https://invent.kde.org/network/ktorrent/-/merge_requests/153

Comment 3 Jack Hill 2025-08-08 22:56:07 UTC

Git commit 4510509950c10beda3ff7d409efe8f33a71d9ebc by Jack Hill.
Committed on 08/08/2025 at 22:56.
Pushed by jackh into branch 'master'.

Fix issue of constantly writing to the magnets file.

Basically MagnetManager was constantly emitting `update`, even if it
hadn't updated. I've removed the bad emit and added a test to ensure the
signal is only emitted when needed.

M  +5    -0    libktcore/autotests/CMakeLists.txt
A  +220  -0    libktcore/autotests/magnetmanagertest.cpp     [License: GPL(v2.0+)]
M  +0    -2    libktcore/torrent/magnetmanager.cpp

https://invent.kde.org/network/ktorrent/-/commit/4510509950c10beda3ff7d409efe8f33a71d9ebc

Comment 4 Jack Hill 2025-08-08 23:03:13 UTC

Git commit ebeaf20737bd9b02ac703e243ae2b9aef7ed32e0 by Jack Hill.
Committed on 08/08/2025 at 23:03.
Pushed by jackh into branch 'release/25.08'.

Fix issue of constantly writing to the magnets file.

Basically MagnetManager was constantly emitting `update`, even if it
hadn't updated. I've removed the bad emit and added a test to ensure the
signal is only emitted when needed.
FIXED-IN: 25.08.1

(cherry picked from commit 4510509950c10beda3ff7d409efe8f33a71d9ebc)

Co-authored-by: Jack Hill <jackhill3103@gmail.com>

M  +5    -0    libktcore/autotests/CMakeLists.txt
A  +220  -0    libktcore/autotests/magnetmanagertest.cpp     [License: GPL(v2.0+)]
M  +0    -2    libktcore/torrent/magnetmanager.cpp

https://invent.kde.org/network/ktorrent/-/commit/ebeaf20737bd9b02ac703e243ae2b9aef7ed32e0