Ports from (https://github.com/TrinityCore/TrinityCore)

Core/Unit: don't clear low health aura states on death
Core/Gossip: Fix gossip bug on modify money
Core/Spells: Change the radius of PBAoEs following the feedback received on
Core/Player: update interaction checks, some info taken from client
Core/Spell: abort channeling if no valid targets are found after searching
Core/Creature: fix _DespawnAtEvade saving wrong respawn time
Core/Spell: fixed some problems with per caster aura states
Quickfix a bug introduced by 2f19d97 which prevented GTAoE from being cast.
Core/SmartAI: allow SMART_ACTION_SEND_GOSSIP_MENU to override default gossip
Core/Spell: in case of immunity, check all effects to choose correct procFlags, as none has technically hit
Fix evade issues when a spell hits the target just before evading.
Scripts/Command: implement .debug play music command
Partial revert, Unit::getAttackerForHelper() shouldn't return units that we aren't in combat with (victim can be such a unit for players/player pets, which can startattack from a distance without entering combat).
Fix an issue where CanSpawn would never get invoked on creatures without per-guid script.
Core/Players: fix null dereference crash

Source/Game/Entities/Creature/Creature.cs

@@ -1695,27 +1695,34 @@ namespace Game.Entities
         {
             if (timeMSToDespawn != 0)
             {
-                ForcedDespawnDelayEvent pEvent = new ForcedDespawnDelayEvent(this, forceRespawnTimer);
-
-                m_Events.AddEvent(pEvent, m_Events.CalculateTime(timeMSToDespawn));
+                m_Events.AddEvent(new ForcedDespawnDelayEvent(this, forceRespawnTimer), m_Events.CalculateTime(timeMSToDespawn));
                 return;
             }
 
+            uint corpseDelay = GetCorpseDelay();
+            uint respawnDelay = GetRespawnDelay();
+
             // do it before killing creature
             DestroyForNearbyPlayers();
 
+            bool overrideRespawnTime = false;
             if (IsAlive())
-                SetDeathState(DeathState.JustDied);
-
-            bool overrideRespawnTime = true;
-            if (forceRespawnTimer > TimeSpan.Zero)
             {
-                SetRespawnTime((uint)forceRespawnTimer.TotalSeconds);
-                overrideRespawnTime = false;
+                if (forceRespawnTimer > TimeSpan.Zero)
+                {
+                    SetCorpseDelay(0);
+                    SetRespawnDelay((uint)forceRespawnTimer.TotalSeconds);
+                    overrideRespawnTime = false;
+                }
+
+                SetDeathState(DeathState.JustDied);
             }
 
             // Skip corpse decay time
             RemoveCorpse(overrideRespawnTime, false);
+
+            SetCorpseDelay(corpseDelay);
+            SetRespawnDelay(respawnDelay);
         }
 
         public void DespawnOrUnsummon(TimeSpan time, TimeSpan forceRespawnTimer = default) { DespawnOrUnsummon((uint)time.TotalMilliseconds, forceRespawnTimer); }
@@ -2060,14 +2067,9 @@ namespace Game.Entities
             Unit targetVictim = target.GetAttackerForHelper();
 
             // if I'm already fighting target, or I'm hostile towards the target, the target is acceptable
-            if (GetVictim() == target || IsHostileTo(target))
+            if (IsInCombatWith(target) || IsHostileTo(target))
                 return true;
 
-            // a player is targeting me, but I'm not hostile towards it, and not currently attacking it, the target is not acceptable
-            // (players may set their victim from a distance, and doesn't mean we should attack)
-            if (target.GetTypeId() == TypeId.Player && targetVictim == this)
-                return false;
-
             // if the target's victim is friendly, and the target is neutral, the target is acceptable
             if (targetVictim != null && IsFriendlyTo(targetVictim))
                 return true;

Source/Game/Entities/Player/Player.Quest.cs

@@ -1824,7 +1824,6 @@ namespace Game.Entities
             List<uint> qr;
             List<uint> qir;
 
-            PlayerTalkClass.ClearMenus();
             switch (questgiver.GetTypeId())
             {
                 case TypeId.GameObject:

Source/Game/Entities/Player/Player.cs

@@ -3615,19 +3615,24 @@ namespace Game.Entities
 
         void ResurrectUsingRequestDataImpl()
         {
+            // save health and mana before resurrecting, _resurrectionData can be erased
+            uint resurrectHealth = _resurrectionData.Health;
+            uint resurrectMana = _resurrectionData.Mana;
+            uint resurrectAura = _resurrectionData.Aura;
+            ObjectGuid resurrectGUID = _resurrectionData.GUID;
+
             ResurrectPlayer(0.0f, false);
 
-            SetHealth(_resurrectionData.Health);
-            SetPower(PowerType.Mana, (int)_resurrectionData.Mana);
+            SetHealth(resurrectHealth);
+            SetPower(PowerType.Mana, (int)resurrectMana);
 
             SetPower(PowerType.Rage, 0);
             SetFullPower(PowerType.Energy);
             SetFullPower(PowerType.Focus);
             SetPower(PowerType.LunarPower, 0);
 
-            uint aura = _resurrectionData.Aura;
-            if (aura != 0)
-                CastSpell(this, aura, true, null, null, _resurrectionData.GUID);
+            if (resurrectAura != 0)
+                CastSpell(this, resurrectAura, true, null, null, resurrectGUID);
 
             SpawnCorpseBones();
         }
@@ -5562,8 +5567,8 @@ namespace Game.Entities
             if (creature.GetReactionTo(this) <= ReputationRank.Unfriendly)
                 return null;
 
-            // not too far
-            if (!creature.IsWithinDistInMap(this, SharedConst.InteractionDistance))
+            // not too far, taken from CGGameUI::SetInteractTarget
+            if (!creature.IsWithinDistInMap(this, creature.GetCombatReach() + 4.0f))
                 return null;
 
             return creature;
@@ -5571,34 +5576,36 @@ namespace Game.Entities
 
         public GameObject GetGameObjectIfCanInteractWith(ObjectGuid guid)
         {
-            GameObject go = GetMap().GetGameObject(guid);
-            if (go)
-            {
-                if (go.IsWithinDistInMap(this, go.GetInteractionDistance()))
-                    return go;
+            if (guid.IsEmpty())
+                return null;
 
-                Log.outDebug(LogFilter.Maps, "Player.GetGameObjectIfCanInteractWith: GameObject '{0}' ({1}) is too far away from player '{2}' ({3}) to be used by him (Distance: {4}, maximal {5} is allowed)",
-                    go.GetName(), go.GetGUID().ToString(), GetName(), GetGUID().ToString(), go.GetDistance(this), go.GetInteractionDistance());
-            }
+            if (!IsInWorld)
+                return null;
 
-            return null;
+            if (IsInFlight())
+                return null;
+
+            // exist
+            GameObject go = ObjectAccessor.GetGameObject(this, guid);
+            if (go == null)
+                return null;
+
+            if (!go.IsWithinDistInMap(this, go.GetInteractionDistance()))
+                return null;
+
+            return go;
         }
+
         public GameObject GetGameObjectIfCanInteractWith(ObjectGuid guid, GameObjectTypes type)
         {
-            GameObject go = GetMap().GetGameObject(guid);
-            if (go != null)
-            {
-                if (go.GetGoType() == type)
-                {
-                    if (go.IsWithinDistInMap(this, go.GetInteractionDistance()))
-                        return go;
+            GameObject go = GetGameObjectIfCanInteractWith(guid);
+            if (!go)
+                return null;
 
-                    Log.outDebug(LogFilter.Maps, "Player.GetGameObjectIfCanInteractWith: GameObject '{0}' ({1}) is too far away from player '{2}' ({3}) to be used by him (Distance: {4}, maximal {5} is allowed)",
-                        go.GetName(), go.GetGUID().ToString(), GetName(), GetGUID().ToString(), go.GetDistance(this), go.GetInteractionDistance());
-                }
-            }
+            if (go.GetGoType() != type)
+                return null;
 
-            return null;
+            return go;
         }
 
         public void SendInitialPacketsBeforeAddToMap()

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -376,6 +376,11 @@ namespace Game.Entities
             if (IsTypeId(TypeId.Player) && IsMounted())
                 return false;
 
+            Creature creature = ToCreature();
+            // creatures cannot attack while evading
+            if (creature != null && creature.IsInEvadeMode())
+                return false;
+
             if (HasUnitFlag(UnitFlags.Pacified))
                 return false;
 
@@ -436,7 +441,7 @@ namespace Game.Entities
             if (meleeAttack)
                 AddUnitState(UnitState.MeleeAttacking);
 
-            if (IsTypeId(TypeId.Unit) && !IsPet())
+            if (creature != null && !IsPet())
             {
                 // should not let player enter combat by right clicking target - doesn't helps
                 AddThreat(victim, 0.0f);
@@ -445,8 +450,8 @@ namespace Game.Entities
                 if (victim.IsTypeId(TypeId.Player))
                     victim.SetInCombatWith(this);
 
-                ToCreature().SendAIReaction(AiReaction.Hostile);
-                ToCreature().CallAssistance();
+                creature.SendAIReaction(AiReaction.Hostile);
+                creature.CallAssistance();
 
                 // Remove emote state - will be restored on creature reset
                 SetEmoteState(Emote.OneshotNone);
@@ -536,12 +541,28 @@ namespace Game.Entities
         }
         public Unit GetAttackerForHelper()
         {
-            if (GetVictim() != null)
-                return GetVictim();
+            Unit victim = GetVictim();
+            if (victim != null)
+                if (!IsControlledByPlayer() || IsInCombatWith(victim) || victim.IsInCombatWith(this))
+                    return victim;
 
-            if (attackerList.Count != 0)
+            if (!attackerList.Empty())
                 return attackerList[0];
 
+            Player owner = GetCharmerOrOwnerPlayerOrPlayerItself();
+            if (owner != null)
+            {
+                HostileReference refe = owner.GetHostileRefManager().GetFirst();
+                while (refe != null)
+                {
+                    Unit hostile = refe.GetSource().GetOwner();
+                    if (hostile != null)
+                        return hostile;
+
+                    refe = refe.Next();
+                }
+            }
+
             return null;
         }
         public List<Unit> GetAttackers()

Source/Game/Entities/Unit/Unit.Spells.cs

@@ -3965,9 +3965,22 @@ namespace Game.Entities
                     ToTotem().SetDeathState(DeathState.JustDied);
             }
 
-            // Remove aurastates only if were not found
-            if (!auraStateFound)
-                ModifyAuraState(auraState, false);
+            // Remove aurastates only if needed and were not found
+            if (auraState != 0)
+            {
+                if (!auraStateFound)
+                    ModifyAuraState(auraState, false);
+                else
+                {
+                    // update for casters, some shouldn't 'see' the aura state
+                    uint aStateMask = (1u << ((int)auraState - 1));
+                    if ((aStateMask & (uint)AuraStateType.PerCasterAuraStateMask) != 0)
+                    {
+                        m_values.ModifyValue(m_unitData).ModifyValue(m_unitData.AuraState);
+                        ForceUpdateFieldChange();
+                    }
+                }
+            }
 
             aura.HandleAuraSpecificMods(aurApp, caster, false, false);
         }
@@ -4099,7 +4112,17 @@ namespace Game.Entities
             // Update target aura state flag
             AuraStateType aState = aura.GetSpellInfo().GetAuraState();
             if (aState != 0)
-                ModifyAuraState(aState, true);
+            {
+                uint aStateMask = (1u << ((int)aState - 1));
+                // force update so the new caster registers it
+                if (aStateMask.HasAnyFlag((uint)AuraStateType.PerCasterAuraStateMask) && (m_unitData.AuraState & aStateMask) != 0)
+                {
+                    m_values.ModifyValue(m_unitData).ModifyValue(m_unitData.AuraState);
+                    ForceUpdateFieldChange();
+                }
+                else
+                    ModifyAuraState(aState, true);
+            }
 
             if (aurApp.HasRemoveMode())
                 return;

Source/Game/Entities/Unit/Unit.cs

@@ -1626,8 +1626,6 @@ namespace Game.Entities
 
             if (s == DeathState.JustDied)
             {
-                ModifyAuraState(AuraStateType.HealthLess20Percent, false);
-                ModifyAuraState(AuraStateType.HealthLess35Percent, false);
                 // remove aurastates allowing special moves
                 ClearAllReactives();
                 m_Diminishing.Clear();