[pjerra]

After a raid-walk --place, two seats in every Zul'Gurub Jin'do raid stood frozen at the placement point for the whole first fight. This happened in walks 54 and 55, in 20 of 20 raids. Fights with the pair frozen won 22 % of the time; fights without it won 50-71 %.

Cause. A live repro on a test server found it. The spread=5 place drops those seats onto a small navmesh island next to the step-516 place point, and that island is disconnected from the rest of the mesh. From there every move fails with NOPATH (reach spell / reach melee return dispatch-short path=0x8). An offline path-check confirms there is no path.

Change: the unfreeze check. From 15 s to 120 s after the first watch sample following a place, the walk judges every hire. The judging uses the poll's own time, with a freshness limit of 15 s. A hire counts as frozen when all of these hold:

• it has stood within 2 yd of the same spot for 10 s;
• it is inside spread+6 yd of the place point;
• it is more than 35 yd from the MT;
• the MT is more than 15 yd from the place point.

The 35 yd figure comes from the repro: the frozen pair was 58-60 yd from the MT's first fight.

Re-place. The commander goes .go xyz onto the MT at z+2. The walk waits for the landing to be confirmed within 5 yd, then .summons the hire. Limits:

• at most 2 re-places per hire;
• at most 3 failed summons per hire, 5 s apart;
• at most 3 .go failures in a row;
• the check stops on MT death or a wipe.

Every placement move re-arms the check (retry, retreat, reuse or bind gather), and the old arm's summary line is written first.

Logs. placement: re-placed <bot> (frozen at x,y,z for <s>s), failure lines, and a closing placement: frozen=<n> re-placed=<n>.

Flag. On by default for --place; turn it off with --no-place-unfreeze.

Known limits:

• A .summon counts as done when the GM line is sent. The walk does not wait for the hire's new position. The walk report's FROZEN-AT-PLACE flag catches a hire that stayed frozen.
• The commander stays beside the MT, possibly inside its fight.

Tests. Table tests for the frozen rule, plus driver tests through the real pollOnce with frames 6-13 s old. They cover:

• a caster near the point that is not frozen;
• a landing delayed past 500 ms;
• summon and .go failures;
• the window start;
• re-arms;
• a wipe, a dead MT, and die-and-revive;
• two frozen hires in one tick.

Mutations on each rule were caught. vm-test ta passes in full, and the targeted -race run (Unfreeze|FrozenBots|TestPlace|TestParse) passes.

Reviews. Codex adversarial plus a cold review, three rounds.