Core: Combat/threat system rewrite (PR #19930)

- PvE combat is now always mutual. UNIT_FLAG_IN_COMBAT is backed by actual references to the units we're in combat with.
- PvP combat is now also tracked, and almost always mutual; spells like Vanish and Feign Death can break this rule. That means we can easily determine a list of players we're fighting.
- By extension, IsInCombatWith now has sensible behavior when invoked on nonplayers.
- Threat and combat systems are no longer the same.
  - They still have an enforced relationship (threat implies combat - clearing combat clears threat)...
  - ...but we can have combat without threat. A creature (with threat list) isn't considered to be engaged until it has an entry on its threat list...
  - ...which means we can now faithfully replicate retail engage behavior. Combat on projectile launch - engagement start on projectile impact. Yay for progress!
- AI method refactor, as already ported in 6113b9d - `JustEngagedWith`, `JustEnteredCombat` and `JustExitedCombat`.
- Vehicle threat is now properly pooled on the main vehicle body (fixes #16542).
- Various edge case bug fixes for threat redirects (Misdirection "cancelling" Vigilance and similar).
- Target re-selection is now significantly faster.
- Fixed a ton of other smaller edge case bugs, probably.

Closes #7951 and #19998.

(cherry picked from commit 532ab1c7f8653d1a2e48aa1f1f8a9ba1041d4bb7)

1 files changed, 0 insertions, 3 deletions

diff --git a/src/server/game/Handlers/PetHandler.cpp b/src/server/game/Handlers/PetHandler.cpp
index 9a2863ae12c..c38a63201b1 100644
--- a/src/server/game/Handlers/PetHandler.cpp
+++ b/src/server/game/Handlers/PetHandler.cpp
@@ -134,7 +134,6 @@ void WorldSession::HandlePetStopAttack(WorldPackets::Pet::PetStopAttack& packet)
         return;
 
     pet->AttackStop();
-    pet->ClearInPetCombat();
 }
 
 void WorldSession::HandlePetActionHelper(Unit* pet, ObjectGuid guid1, uint32 spellid, uint16 flag, ObjectGuid guid2, Position const& pos)
@@ -168,7 +167,6 @@ void WorldSession::HandlePetActionHelper(Unit* pet, ObjectGuid guid1, uint32 spe
                 case COMMAND_FOLLOW:                        //spellid=1792  //FOLLOW
                     pet->AttackStop();
                     pet->InterruptNonMeleeSpells(false);
-                    pet->ClearInPetCombat();
                     pet->GetMotionMaster()->MoveFollow(_player, PET_FOLLOW_DIST, pet->GetFollowAngle());
                     charmInfo->SetCommandState(COMMAND_FOLLOW);
 
@@ -282,7 +280,6 @@ void WorldSession::HandlePetActionHelper(Unit* pet, ObjectGuid guid1, uint32 spe
             {
                 case REACT_PASSIVE:                         //passive
                     pet->AttackStop();
-                    pet->ClearInPetCombat();
                     /* fallthrough */
                 case REACT_DEFENSIVE:                       //recovery
                 case REACT_AGGRESSIVE:                      //activete