Sometimes units are stuck in a loop trying to pass left and right of each other

[ffm]

Sometimes a unit tries to pass another unit but cant because the units stuck in a loop trying to pass left and right of each other.

In Carrier Sense Multiple Access the collision problem is solved by waiting a random backoff period. ​https://en.wikipedia.org/wiki/Carrier_sense_multiple_access_with_collision_detection

if last_redirection_of_this_Unit < Time_1_second
  unit_hold(randomTime_between_0_and_0.5_seconds)
endif

The Bug would happen less frequently if the unit carrying the resource has a higher priority has a higher priority than the unit on the way to gather resources, so lower prioritized unit makes way for the other one, as proposed in Ticket #3442.

[elexis]

This bug exists at least since alpha 17, so it's not caused by the new pathfinder.

I distinctly remember merchantships having that problem on the random map script Latium. Two of them were sufficient to loop indefinitely.

[Lionkanzen]

Exist at last since Alpha 7 is very older bug.( ignored for very long time)

[elexis]

British merchant ships blocking each other on r17108. Exactly that bug.

[elexis]

As seen in the replay above.

[elexis]

Getting humans stuck is rather rare as they have a small radius.

[elexis]

Replay as seen on the gif above, r17131

[elexis]

Might be easier to fix by implementing #3442. If two colliding units have the same priority, roll the dice who may pass.

[wraitii]

Bumping for A20 given the pathfinder fixes: does this still happen? I guess nothing is actually preventing it.

[elexis]

Replying to wraitii:

Bumping for A20 given the pathfinder fixes: does this still happen?

Since the replay is only 40 commits old, I'm pretty sure this still happens. The bug has also persistently survived all pathfinder changes since ages.

[elexis]

Backlogging due to lack of progress.

[Freagarach]

This won't happen anymore since the current UnitMotion system will let moving units pass through eachother.

​https://code.wildfiregames.com/rP25182 / r25182