Core/AI: Finally move the "is creature engaged" flag to be a property of the creature AI, where it honestly always belonged. Fixes #17981 and #23602 for real this time.

(cherry picked from commit 0e7c66cb4c7ff7d44e232d0b50703a48605ffd24)

1 files changed, 40 insertions, 4 deletions

diff --git a/src/server/game/AI/CreatureAI.cpp b/src/server/game/AI/CreatureAI.cpp
index e1d53238c89..7d617a9c384 100644
--- a/src/server/game/AI/CreatureAI.cpp
+++ b/src/server/game/AI/CreatureAI.cpp
@@ -43,7 +43,7 @@ AISpellInfoType* GetAISpellInfo(uint32 spellId, Difficulty difficulty)
 
 CreatureAI::CreatureAI(Creature* creature, uint32 scriptId)
     : UnitAI(creature), me(creature), _boundary(nullptr),
-      _negateBoundary(false), _scriptId(scriptId ? scriptId : creature->GetScriptId()), _moveInLOSLocked(false)
+      _negateBoundary(false), _scriptId(scriptId ? scriptId : creature->GetScriptId()), _isEngaged(false), _moveInLOSLocked(false)
 {
     ASSERT(_scriptId, "A CreatureAI was initialized with an invalid scriptId!");
 }
@@ -207,6 +207,12 @@ void CreatureAI::JustAppeared()
     }
 }
 
+void CreatureAI::JustEnteredCombat(Unit* who)
+{
+    if (!IsEngaged() && !me->CanHaveThreatList())
+        EngagementStart(who);
+}
+
 void CreatureAI::EnterEvadeMode(EvadeReason why)
 {
     if (!_EnterEvadeMode(why))
@@ -235,7 +241,7 @@ void CreatureAI::EnterEvadeMode(EvadeReason why)
 
 bool CreatureAI::UpdateVictim()
 {
-    if (!me->IsEngaged())
+    if (!IsEngaged())
         return false;
 
     if (!me->HasReactState(REACT_PASSIVE))
@@ -257,22 +263,52 @@ bool CreatureAI::UpdateVictim()
     return true;
 }
 
+void CreatureAI::EngagementStart(Unit* who)
+{
+    if (_isEngaged)
+    {
+        TC_LOG_ERROR("scripts.ai", "CreatureAI::EngagementStart called even though creature is already engaged. Creature debug info:\n%s", me->GetDebugInfo().c_str());
+        return;
+    }
+    _isEngaged = true;
+
+    me->AtEngage(who);
+}
+
+void CreatureAI::EngagementOver()
+{
+    if (!_isEngaged)
+    {
+        TC_LOG_ERROR("scripts.ai", "CreatureAI::EngagementOver called even though creature is not currently engaged. Creature debug info:\n%s", me->GetDebugInfo().c_str());
+        return;
+    }
+    _isEngaged = false;
+
+    me->AtDisengage();
+}
+
 bool CreatureAI::_EnterEvadeMode(EvadeReason /*why*/)
 {
+    if (me->IsInEvadeMode())
+        return false;
+
     if (!me->IsAlive())
+    {
+        EngagementOver();
         return false;
+    }
 
     me->RemoveAurasOnEvade();
 
     me->CombatStop(true);
-    me->GetThreatManager().NotifyDisengaged();
     me->SetLootRecipient(nullptr);
     me->ResetPlayerDamageReq();
     me->SetLastDamagedTime(0);
     me->SetCannotReachTarget(false);
     me->DoNotReacquireTarget();
+    EngagementOver();
 
-    return !me->IsInEvadeMode();
+    return true;
 }
 
 Optional<QuestGiverStatus> CreatureAI::GetDialogStatus(Player* /*player*/)