fix(mavlink): reset mission sequence on platform restart

[Sayshara]

Solved Problem

Fixes #14981

After a platform reboot, PX4 could restore the previously persisted mission_state.current_seq from Dataman and continue reporting the old active mission item. As a result, the vehicle could resume a stale waypoint from the previous run, for example a landing waypoint, instead of starting the mission again from the first waypoint.

Solution

Reset the persisted mission_state.current_seq to 0 during MavlinkMissionManager initialization on startup, before the mission state is republished.

This keeps the uploaded mission itself intact:

• mission items remain stored in Dataman
• mission count and mission identifiers remain unchanged
• only the active mission sequence is reset

With this change, after a reboot the platform starts with the same mission, but with the current mission item reset to the first waypoint.

Changelog Entry

For release notes:

Bugfix: Reset persisted mission current waypoint to the first mission item after reboot

[github-actions]

🔎 FLASH Analysis

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Updated: 2026-04-10T12:35:24

[mrpollo]

Have you considered the possibility of the device rebooting mid-mission? Would this lead to undesired behavior?

[Sayshara]

Have you considered the possibility of the device rebooting mid-mission? Would this lead to undesired behavior?

After a reboot the device would be in a non-mission flight mode, disarmed state, no immediate auto continuation of the mission etc.
Of course still considering the case like mid-flight landing, replacing battery and continue mission. Maybe in a future we could allow the user to resume everything autonomously with proper state.

There's a trade-off between safety and shortcuts. I think more intuitive is a fresh mission start rather than resuming a stale waypoint from the previous session.