[Petra-AI] entity is undefined in ApplyEntitiesDelta

[elexis]

In an a18 match with one petra AI, the following errors appeared, beginning on turn 2859. We tried solving it by killing the AI player, but it only changed the error message that was thrown. The chat was completely unusable throughout the whole match.

Turn 2859 (500)... ERROR: JavaScript error: simulation/ai/common-api/shared.js line 348
TypeError: entity is undefined
  m.SharedScript.prototype.ApplyEntitiesDelta@simulation/ai/common-api/shared.js:348:4
  m.SharedScript.prototype.onUpdate@simulation/ai/common-api/shared.js:217:2

Turn 2860 (500)... 
Turn 2861 (500)... WARNING: JavaScript warning: simulation/ai/common-api/entity.js line 538
reference to undefined property entity.template
ERROR: JavaScript error: simulation/ai/common-api/shared.js line 112
TypeError: name is undefined
  m.SharedScript.prototype.GetTemplate@simulation/ai/common-api/shared.js:112:1
  m.Entity<._init@simulation/ai/common-api/entity.js:538:3
  m.SharedScript.prototype.ApplyEntitiesDelta@simulation/ai/common-api/shared.js:266:7
  m.SharedScript.prototype.onUpdate@simulation/ai/common-api/shared.js:217:2

From turn 3679 to 3725 there was a little bit of silence and no errors were thrown, just to continue with different errors thereafter:

TypeError: ent is undefined
  m.getMaxStrength@simulation/ai/petra/entity-extend.js:8:6
  m.Army.prototype.evaluateStrength@simulation/ai/petra/army.js:94:6
  m.Army.prototype.recalculateStrengths@simulation/ai/petra/army.js:88:3
  m.Army.prototype.merge@simulation/ai/petra/army.js:284:2
  m.DefenseManager.prototype.checkEnemyArmies@simulation/ai/petra/defenseManager.js:181:5
  m.DefenseManager.prototype.update@simulation/ai/petra/defenseManager.js:20:2
  m.HQ.prototype.update@simulation/ai/petra/headquarters.js:1801:2
  m.PetraBot.prototype.OnUpdate@simulation/ai/petra/_petrabot.js:123:3
  m.BaseAI.prototype.HandleMessage@simulation/ai/common-api/baseAI.js:83:2

Commands.txt and replay log attached. The error is reproducable with that commands.txt.

[mimo]

I think this is a dupplicate of #3178, itself a dupplicate of #3142, and the problem is already fixed in svn.