This fixes a regression introduced by 055c848c1a: when an entity is
ordered to move to a target within short path distance (or direct path
distance), it no longer computed at least one long path, which meant it
could be stuck forever if the target was not actually reachable (such as
behind a wall).
To fix this, compute a long path after 3 failed computations, which
should result in a delay of 1-3 turns. The previous code did this after
1 failed try - the decision to make it 3 is mostly based on the idea
that in most cases, being stuck means we ran into units, not that we
were ordered somewhere close. Should there be complaints, it could be
lowered to 2 or 1.
This fixes a second issue, reported in #4473: units sometimes get stuck,
particularly when trying to garrison a turret from 'inside' the walls.
The issue is that the turret is not accessible via the inside as its
obstruction + garrison range is blocked by the surrounding walls.
However, as introduced by 6e05a00929, TryGoingStraightToTargetEntity
ignores all entities with the obstruction group of the target (the
reason for this being that otherwise it would never succeed, since the
line towards the target would likely go through the target).
For walls and formations, this means ignoring possibly too many
entities, and in the case of #4473, ignoring wall pieces. The unit thus
mistakenly thought it could direct-path to the turret, and got stuck.
To fix this, we can ignore specifically the targeted entity's
obstruction tag. This can be considered a fix to 6e05a00929.
temple accepted an earlier version of this patch (specifically elexis'
version).
Fixes#4473
Based on a patch by: elexis
Differential Revision: https://code.wildfiregames.com/D1424
This was SVN commit r22533.
7a823ca671