Core/Creatures: Various fixes for creatures, regarding combat conditions, despawning, and few others (#18998)

* Made some changes to kiting mechanics, simplified code and made taunt auras prolong combat no matter the distance from the spawn
Unified some creature despawning code, removed some brutal direct calls in scripts
Don't play death anim on forced despawn
Removed some redundant visibility changes on creature despawn
Fixed possible problem with pet initializing template info from difficulty greater than normal
Properly keep UNIT_FLAG_IN_COMBAT on UpdateEntry call
Moved RegenerateMana function to general Regenerate(Power) function
Fixed increased health regeneration from polymorph for pets
Implemented CREATURE_TYPE_FLAG_GHOST_VISIBLE, those creatures will be properly seen when player is dead also
Removed hackfix from Gaeriyan and Franclorn Forgewright, fixed properly
Simplified ForcedRespawnTime code in ForcedDespawn
Do not allow to assist unit while evading or when enemy is evading
Do not allow to attack other units when evading or when the unit is evading
Corrected distance checking code before creature is allowed to evade, should fix some common problems
Properly return summon position for summoned creatures as their respawn position
Properly stop all moving units on gossip hello, no matter their npc flags

22 files changed, 72 insertions, 65 deletions

diff --git a/src/server/scripts/Commands/cs_pet.cpp b/src/server/scripts/Commands/cs_pet.cpp
index d658876d822..1b704e29b06 100644
--- a/src/server/scripts/Commands/cs_pet.cpp
+++ b/src/server/scripts/Commands/cs_pet.cpp
@@ -93,8 +93,7 @@ public:
             return false;
         }
 
-        creatureTarget->setDeathState(JUST_DIED);
-        creatureTarget->RemoveCorpse();
+        creatureTarget->DespawnOrUnsummon();
         creatureTarget->SetHealth(0); // just for nice GM-mode view
 
         pet->SetGuidValue(UNIT_FIELD_CREATEDBY, player->GetGUID());
diff --git a/src/server/scripts/EasternKingdoms/Gnomeregan/gnomeregan.cpp b/src/server/scripts/EasternKingdoms/Gnomeregan/gnomeregan.cpp
index 0ff1744457e..eb65bf1dfb3 100644
--- a/src/server/scripts/EasternKingdoms/Gnomeregan/gnomeregan.cpp
+++ b/src/server/scripts/EasternKingdoms/Gnomeregan/gnomeregan.cpp
@@ -193,10 +193,7 @@ public:
                 {
                     if (Creature* summon = ObjectAccessor::GetCreature(*me, *itr))
                     {
-                        if (summon->IsAlive())
-                            summon->DisappearAndDie();
-                        else
-                            summon->RemoveCorpse();
+                        summon->DespawnOrUnsummon();
                     }
                 }
         }
diff --git a/src/server/scripts/EasternKingdoms/Karazhan/karazhan.cpp b/src/server/scripts/EasternKingdoms/Karazhan/karazhan.cpp
index 8f1e35a0219..264a21d880f 100644
--- a/src/server/scripts/EasternKingdoms/Karazhan/karazhan.cpp
+++ b/src/server/scripts/EasternKingdoms/Karazhan/karazhan.cpp
@@ -479,8 +479,7 @@ public:
             }
             else
             {
-                me->DealDamage(me, me->GetHealth(), NULL, DIRECT_DAMAGE, SPELL_SCHOOL_MASK_NORMAL, NULL, false);
-                me->RemoveCorpse();
+                me->DespawnOrUnsummon();
             }
         }
         void EnterCombat(Unit* /*who*/) override { }
diff --git a/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp b/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp
index 53569bdce2a..f2941a5b314 100644
--- a/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp
+++ b/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp
@@ -502,9 +502,7 @@ public:
                     me->SummonCreature(NPC_DEAD, x, y, z, 0, TEMPSUMMON_TIMED_DESPAWN_OUT_OF_COMBAT, 5000);
                 }
                 (*i)->SetVisible(false);
-                (*i)->setDeathState(JUST_DIED);
-                if ((*i)->getDeathState() == CORPSE)
-                    (*i)->RemoveCorpse();
+                (*i)->DespawnOrUnsummon();
             }
         }
     };
diff --git a/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_kiljaeden.cpp b/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_kiljaeden.cpp
index fb587cdd6e5..77b3da4eece 100644
--- a/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_kiljaeden.cpp
+++ b/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_kiljaeden.cpp
@@ -1168,8 +1168,7 @@ public:
                         uiTimer = 5000;
                         break;
                     case 3:
-                        me->KillSelf();
-                        me->RemoveCorpse();
+                        me->DespawnOrUnsummon();
                         break;
                 }
             } else uiTimer -=diff;
diff --git a/src/server/scripts/EasternKingdoms/Uldaman/instance_uldaman.cpp b/src/server/scripts/EasternKingdoms/Uldaman/instance_uldaman.cpp
index bbed195508b..854f42e16cd 100644
--- a/src/server/scripts/EasternKingdoms/Uldaman/instance_uldaman.cpp
+++ b/src/server/scripts/EasternKingdoms/Uldaman/instance_uldaman.cpp
@@ -222,8 +222,8 @@ class instance_uldaman : public InstanceMapScript
                     Creature* target = instance->GetCreature(*i);
                     if (!target || target->isDead() || target->getFaction() != 14)
                         continue;
-                    target->setDeathState(JUST_DIED);
-                    target->RemoveCorpse();
+
+                    target->DespawnOrUnsummon();
                 }
 
                 // Vault Walkers
@@ -232,8 +232,8 @@ class instance_uldaman : public InstanceMapScript
                     Creature* target = instance->GetCreature(*i);
                     if (!target || target->isDead() || target->getFaction() != 14)
                         continue;
-                    target->setDeathState(JUST_DIED);
-                    target->RemoveCorpse();
+
+                    target->DespawnOrUnsummon();
                 }
 
                 // Earthen Guardians
@@ -242,8 +242,8 @@ class instance_uldaman : public InstanceMapScript
                     Creature* target = instance->GetCreature(*i);
                     if (!target || target->isDead() || target->getFaction() != 14)
                         continue;
-                    target->setDeathState(JUST_DIED);
-                    target->RemoveCorpse();
+
+                    target->DespawnOrUnsummon();
                 }
             }
 
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_anetheron.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_anetheron.cpp
index c3fdb7b12f8..9965053bfc6 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_anetheron.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_anetheron.cpp
@@ -239,8 +239,7 @@ public:
                     Creature* boss = ObjectAccessor::GetCreature(*me, AnetheronGUID);
                     if (!boss || boss->isDead())
                     {
-                        me->setDeathState(JUST_DIED);
-                        me->RemoveCorpse();
+                        me->DespawnOrUnsummon();
                         return;
                     }
                 }
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_azgalor.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_azgalor.cpp
index 7e25fe6b384..e8ba1f90d37 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_azgalor.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/boss_azgalor.cpp
@@ -248,8 +248,7 @@ public:
                     Creature* boss = ObjectAccessor::GetCreature(*me, AzgalorGUID);
                     if (!boss || boss->isDead())
                     {
-                        me->setDeathState(JUST_DIED);
-                        me->RemoveCorpse();
+                        me->DespawnOrUnsummon();
                         return;
                     }
                 }
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal_trash.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal_trash.cpp
index db68dfced7c..7eec37758ee 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal_trash.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal_trash.cpp
@@ -574,8 +574,7 @@ public:
             {
                 if ((faction == 0 && LastOverronPos == 17) || (faction == 1 && LastOverronPos == 21))
                 {
-                    me->setDeathState(DEAD);
-                    me->RemoveCorpse();
+                    me->DespawnOrUnsummon();
                 }
             }
         }
@@ -674,8 +673,7 @@ public:
                 me->SetUInt32Value(UNIT_NPC_EMOTESTATE, EMOTE_ONESHOT_ATTACK_UNARMED);
                 if ((faction == 0 && LastOverronPos == 17) || (faction == 1 && LastOverronPos == 21))
                 {
-                    me->setDeathState(DEAD);
-                    me->RemoveCorpse();
+                    me->DespawnOrUnsummon();
                 }
             }
         }
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
index 6a15068e329..2f76b20ea30 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
@@ -203,8 +203,7 @@ public:
                     //if we reach this it means event was running but at some point reset.
                     if (instance->GetData(TYPE_MEDIVH) == NOT_STARTED)
                     {
-                        me->DealDamage(me, me->GetHealth(), NULL, DIRECT_DAMAGE, SPELL_SCHOOL_MASK_NORMAL, NULL, false);
-                        me->RemoveCorpse();
+                        me->DespawnOrUnsummon();
                         me->Respawn();
                         return;
                     }
diff --git a/src/server/scripts/Kalimdor/TempleOfAhnQiraj/boss_skeram.cpp b/src/server/scripts/Kalimdor/TempleOfAhnQiraj/boss_skeram.cpp
index 26ccc6a9c8e..116f634893f 100644
--- a/src/server/scripts/Kalimdor/TempleOfAhnQiraj/boss_skeram.cpp
+++ b/src/server/scripts/Kalimdor/TempleOfAhnQiraj/boss_skeram.cpp
@@ -128,7 +128,7 @@ class boss_skeram : public CreatureScript
                 if (!me->IsSummon())
                     Talk(SAY_DEATH);
                 else
-                    me->RemoveCorpse();
+                    me->DespawnOrUnsummon();
             }
 
             void EnterCombat(Unit* /*who*/) override
diff --git a/src/server/scripts/Kalimdor/zone_silithus.cpp b/src/server/scripts/Kalimdor/zone_silithus.cpp
index 65fde0e6631..c0322c98eec 100644
--- a/src/server/scripts/Kalimdor/zone_silithus.cpp
+++ b/src/server/scripts/Kalimdor/zone_silithus.cpp
@@ -932,7 +932,7 @@ public:
 
 void npc_qiraj_war_spawn::npc_qiraj_war_spawnAI::JustDied(Unit* /*slayer*/)
 {
-    me->RemoveCorpse();
+    me->DespawnOrUnsummon();
 
     if (!MobGUID)
         return;
diff --git a/src/server/scripts/Northrend/Naxxramas/boss_four_horsemen.cpp b/src/server/scripts/Northrend/Naxxramas/boss_four_horsemen.cpp
index b0abb6e04ad..3db0b1d4fca 100644
--- a/src/server/scripts/Northrend/Naxxramas/boss_four_horsemen.cpp
+++ b/src/server/scripts/Northrend/Naxxramas/boss_four_horsemen.cpp
@@ -264,7 +264,7 @@ struct boss_four_horsemen_baseAI : public BossAI
             {
                 if (Creature* cBoss = getHorsemanHandle(boss))
                 {
-                    cBoss->DespawnOrUnsummon(0);
+                    cBoss->DespawnOrUnsummon();
                     cBoss->SetRespawnTime(15);
                 }
                 else
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_freya.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_freya.cpp
index baa91bad0d9..a3f1189da74 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_freya.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_freya.cpp
@@ -244,7 +244,7 @@ class npc_iron_roots : public CreatureScript
                     target->RemoveAurasDueToSpell(SPELL_ROOTS_FREYA);
                 }
 
-                me->RemoveCorpse(false);
+                me->DespawnOrUnsummon();
             }
 
         private:
diff --git a/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_hydross_the_unstable.cpp b/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_hydross_the_unstable.cpp
index 0bce78607d3..a7b00d4ef70 100644
--- a/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_hydross_the_unstable.cpp
+++ b/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_hydross_the_unstable.cpp
@@ -168,10 +168,7 @@ public:
             for (uint8 i = 0; i < 2; ++i)
             {
                 if (Creature* mob = ObjectAccessor::GetCreature(*me, beams[i]))
-                {
-                    mob->setDeathState(DEAD);
-                    mob->RemoveCorpse();
-                }
+                    mob->DespawnOrUnsummon();
             }
         }
         void EnterCombat(Unit* /*who*/) override
diff --git a/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_lady_vashj.cpp b/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_lady_vashj.cpp
index 00cabcf0d96..febd57cc4fa 100644
--- a/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_lady_vashj.cpp
+++ b/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_lady_vashj.cpp
@@ -805,9 +805,9 @@ public:
                 if (!Vashj || !Vashj->IsAlive() || ENSURE_AI(boss_lady_vashj::boss_lady_vashjAI, Vashj->ToCreature()->AI())->Phase != 3)
                 {
                     // remove
-                    me->setDeathState(DEAD);
-                    me->RemoveCorpse();
                     me->setFaction(35);
+                    me->DespawnOrUnsummon();
+                    return;
                 }
 
                 CheckTimer = 1000;
diff --git a/src/server/scripts/Outland/HellfireCitadel/ShatteredHalls/boss_warchief_kargath_bladefist.cpp b/src/server/scripts/Outland/HellfireCitadel/ShatteredHalls/boss_warchief_kargath_bladefist.cpp
index a4f10aa9eda..08b442e033b 100644
--- a/src/server/scripts/Outland/HellfireCitadel/ShatteredHalls/boss_warchief_kargath_bladefist.cpp
+++ b/src/server/scripts/Outland/HellfireCitadel/ShatteredHalls/boss_warchief_kargath_bladefist.cpp
@@ -176,11 +176,7 @@ class boss_warchief_kargath_bladefist : public CreatureScript
                 {
                     Creature* creature = ObjectAccessor::GetCreature(*me, *itr);
                     if (creature && creature->IsAlive())
-                    {
-                        creature->GetMotionMaster()->Clear(true);
-                        me->DealDamage(creature, creature->GetHealth(), NULL, DIRECT_DAMAGE, SPELL_SCHOOL_MASK_NORMAL, NULL, false);
-                        creature->RemoveCorpse();
-                    }
+                        creature->DespawnOrUnsummon();
                 }
                 adds.clear();
 
@@ -188,11 +184,7 @@ class boss_warchief_kargath_bladefist : public CreatureScript
                 {
                     Creature* creature = ObjectAccessor::GetCreature(*me, *itr);
                     if (creature && creature->IsAlive())
-                    {
-                        creature->GetMotionMaster()->Clear(true);
-                        me->DealDamage(creature, creature->GetHealth(), NULL, DIRECT_DAMAGE, SPELL_SCHOOL_MASK_NORMAL, NULL, false);
-                        creature->RemoveCorpse();
-                    }
+                        creature->DespawnOrUnsummon();
                 }
                 assassins.clear();
             }
diff --git a/src/server/scripts/Outland/TempestKeep/Mechanar/boss_nethermancer_sepethrea.cpp b/src/server/scripts/Outland/TempestKeep/Mechanar/boss_nethermancer_sepethrea.cpp
index 199fa3d81c1..483cf3284c3 100644
--- a/src/server/scripts/Outland/TempestKeep/Mechanar/boss_nethermancer_sepethrea.cpp
+++ b/src/server/scripts/Outland/TempestKeep/Mechanar/boss_nethermancer_sepethrea.cpp
@@ -194,8 +194,8 @@ class npc_ragin_flames : public CreatureScript
                         if (instance->GetData(DATA_NETHERMANCER_SEPRETHREA) != IN_PROGRESS)
                         {
                             //remove
-                            me->setDeathState(JUST_DIED);
-                            me->RemoveCorpse();
+                            me->DespawnOrUnsummon();
+                            return;
                         }
                         Check_Timer = 1000;
                     } else Check_Timer -= diff;
diff --git a/src/server/scripts/Outland/TempestKeep/Mechanar/boss_pathaleon_the_calculator.cpp b/src/server/scripts/Outland/TempestKeep/Mechanar/boss_pathaleon_the_calculator.cpp
index 33ffa66b387..9ddca823d9e 100644
--- a/src/server/scripts/Outland/TempestKeep/Mechanar/boss_pathaleon_the_calculator.cpp
+++ b/src/server/scripts/Outland/TempestKeep/Mechanar/boss_pathaleon_the_calculator.cpp
@@ -231,8 +231,8 @@ class npc_nether_wraith : public CreatureScript
                 {
                     if (Die_Timer <= diff)
                     {
-                        me->setDeathState(JUST_DIED);
-                        me->RemoveCorpse();
+                        me->DespawnOrUnsummon();
+                        return;
                     }
                     else
                         Die_Timer -= diff;
diff --git a/src/server/scripts/Outland/zone_blades_edge_mountains.cpp b/src/server/scripts/Outland/zone_blades_edge_mountains.cpp
index 01a3aa7859a..6a116d89d7a 100644
--- a/src/server/scripts/Outland/zone_blades_edge_mountains.cpp
+++ b/src/server/scripts/Outland/zone_blades_edge_mountains.cpp
@@ -121,11 +121,7 @@ public:
                 return;
 
             if (id == 0)
-            {
-                me->setDeathState(JUST_DIED);
-                me->RemoveCorpse();
-                me->SetHealth(0);
-            }
+                me->DespawnOrUnsummon(1);
         }
 
         void SpellHit(Unit* caster, const SpellInfo* spell) override
@@ -153,7 +149,8 @@ public:
                         EnterEvadeMode();
                         me->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NON_ATTACKABLE);
                         IsNihil = true;
-                    }else
+                    }
+                    else
                         AttackStart(caster);
                 }
             }
diff --git a/src/server/scripts/Outland/zone_shadowmoon_valley.cpp b/src/server/scripts/Outland/zone_shadowmoon_valley.cpp
index 8d517fbe316..3e8b3e4ca95 100644
--- a/src/server/scripts/Outland/zone_shadowmoon_valley.cpp
+++ b/src/server/scripts/Outland/zone_shadowmoon_valley.cpp
@@ -379,7 +379,6 @@ public:
 
             FlyTimer = 10000;
             me->SetDisableGravity(false);
-            me->SetVisible(true);
         }
 
         void SpellHit(Unit* caster, const SpellInfo* spell) override
@@ -423,10 +422,8 @@ public:
 
                     PlayerGUID.Clear();
                 }
-                me->SetVisible(false);
-                me->SetDisableGravity(false);
-                me->DealDamage(me, me->GetHealth(), NULL, DIRECT_DAMAGE, SPELL_SCHOOL_MASK_NORMAL, NULL, false);
-                me->RemoveCorpse();
+
+                me->DespawnOrUnsummon(1);
             }
         }
 
@@ -1192,7 +1189,7 @@ public:
 
         void JustDied(Unit* /*killer*/) override
         {
-            me->RemoveCorpse();
+            me->DespawnOrUnsummon();
             if (Creature* LordIllidan = (ObjectAccessor::GetCreature(*me, LordIllidanGUID)))
                 if (LordIllidan)
                     ENSURE_AI(npc_lord_illidan_stormrage::npc_lord_illidan_stormrageAI, LordIllidan->AI())->LiveCounter();
diff --git a/src/server/scripts/Spells/spell_generic.cpp b/src/server/scripts/Spells/spell_generic.cpp
index fe9277cddf4..c39e91cff42 100644
--- a/src/server/scripts/Spells/spell_generic.cpp
+++ b/src/server/scripts/Spells/spell_generic.cpp
@@ -4386,6 +4386,42 @@ class spell_gen_pony_mount_check : public SpellScriptLoader
         }
 };
 
+class spell_gen_shroud_of_death : public SpellScriptLoader
+{
+    public:
+        spell_gen_shroud_of_death() : SpellScriptLoader("spell_gen_shroud_of_death") { }
+
+        class spell_gen_shroud_of_death_AuraScript : public AuraScript
+        {
+            PrepareAuraScript(spell_gen_shroud_of_death_AuraScript);
+
+            void OnApply(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+            {
+                PreventDefaultAction();
+                GetUnitOwner()->m_serverSideVisibility.SetValue(SERVERSIDE_VISIBILITY_GHOST, GHOST_VISIBILITY_GHOST);
+                GetUnitOwner()->m_serverSideVisibilityDetect.SetValue(SERVERSIDE_VISIBILITY_GHOST, GHOST_VISIBILITY_GHOST);
+            }
+
+            void OnRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+            {
+                PreventDefaultAction();
+                GetUnitOwner()->m_serverSideVisibility.SetValue(SERVERSIDE_VISIBILITY_GHOST, GHOST_VISIBILITY_ALIVE);
+                GetUnitOwner()->m_serverSideVisibilityDetect.SetValue(SERVERSIDE_VISIBILITY_GHOST, GHOST_VISIBILITY_ALIVE);
+            }
+
+            void Register() override
+            {
+                OnEffectApply += AuraEffectApplyFn(spell_gen_shroud_of_death_AuraScript::OnApply, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+                OnEffectRemove += AuraEffectRemoveFn(spell_gen_shroud_of_death_AuraScript::OnRemove, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+            }
+        };
+
+        AuraScript* GetAuraScript() const override
+        {
+            return new spell_gen_shroud_of_death_AuraScript();
+        }
+};
+
 void AddSC_generic_spell_scripts()
 {
     new spell_gen_absorb0_hitlimit1();
@@ -4483,4 +4519,5 @@ void AddSC_generic_spell_scripts()
     new spell_gen_landmine_knockback_achievement();
     new spell_gen_clear_debuffs();
     new spell_gen_pony_mount_check();
+    new spell_gen_shroud_of_death();
 }