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

7 files changed, 15 insertions, 32 deletions

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();