Core/Pools: Fix pools with 1 member never spawning anything anymore (#26620)

* Core/Pools: Fix pools with 1 member never spawning anything anymore

Attempts to fix a 6 years old bug and never fixed by the original author.

* Remove respawn times from db once a respawn has been handled

* Allow to specify if Despawn1Object() should save or not the respawn time. We don't need to do that when respawning an object.

* Apply the same fix to GameObjects too

(cherry picked from commit c8ca48823d45dadb042a80637eff954483dd5328)

4 files changed, 23 insertions, 15 deletions

diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index 5a02af396fc..62b77a930c2 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -1805,9 +1805,12 @@ bool Creature::LoadFromDB(ObjectGuid::LowType spawnId, Map* map, bool addToMap,
                 return false;
             }
         }
+        else
+        {
+            // compatibility mode creatures will be respawned in ::Update()
+            m_deathState = DEAD;
+        }
 
-        // compatibility mode creatures will be respawned in ::Update()
-        m_deathState = DEAD;
         if (CanFly())
         {
             float tz = map->GetHeight(GetPhaseShift(), data->spawnPoint, true, MAX_FALL_DISTANCE);
diff --git a/src/server/game/Maps/Map.cpp b/src/server/game/Maps/Map.cpp
index a0bc1b4cb33..de95c08b4ac 100644
--- a/src/server/game/Maps/Map.cpp
+++ b/src/server/game/Maps/Map.cpp
@@ -3399,6 +3399,7 @@ void Map::ProcessRespawns()
             sPoolMgr->UpdatePool(poolId, next->type, next->spawnId);
 
             // step 3: get rid of the actual entry
+            RemoveRespawnTime(next->type, next->spawnId, nullptr, true);
             delete next;
         }
         else if (CheckRespawn(next)) // see if we're allowed to respawn
@@ -3411,12 +3412,14 @@ void Map::ProcessRespawns()
             DoRespawn(next->type, next->spawnId, next->gridId);
 
             // step 3: get rid of the actual entry
+            RemoveRespawnTime(next->type, next->spawnId, nullptr, true);
             delete next;
         }
         else if (!next->respawnTime)
         { // just remove this respawn entry without rescheduling
             _respawnTimes.pop();
             ASSERT_NOTNULL(GetRespawnMapForType(next->type))->erase(next->spawnId);
+            RemoveRespawnTime(next->type, next->spawnId, nullptr, true);
             delete next;
         }
         else
diff --git a/src/server/game/Pools/PoolMgr.cpp b/src/server/game/Pools/PoolMgr.cpp
index d86421812b3..4bfc918b2af 100644
--- a/src/server/game/Pools/PoolMgr.cpp
+++ b/src/server/game/Pools/PoolMgr.cpp
@@ -186,7 +186,7 @@ void PoolGroup<T>::DespawnObject(ActivePoolData& spawns, uint64 guid, bool alway
 
 // Method that is actualy doing the removal job on one creature
 template<>
-void PoolGroup<Creature>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTime)
+void PoolGroup<Creature>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTime, bool saveRespawnTime)
 {
     if (CreatureData const* data = sObjectMgr->GetCreatureData(guid))
     {
@@ -201,7 +201,7 @@ void PoolGroup<Creature>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTi
                 Creature* creature = itr->second;
                 ++itr;
                 // For dynamic spawns, save respawn time here
-                if (!creature->GetRespawnCompatibilityMode())
+                if (saveRespawnTime && !creature->GetRespawnCompatibilityMode())
                     creature->SaveRespawnTime();
                 creature->AddObjectToRemoveList();
             }
@@ -214,7 +214,7 @@ void PoolGroup<Creature>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTi
 
 // Same on one gameobject
 template<>
-void PoolGroup<GameObject>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTime)
+void PoolGroup<GameObject>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTime, bool saveRespawnTime)
 {
     if (GameObjectData const* data = sObjectMgr->GetGameObjectData(guid))
     {
@@ -230,7 +230,7 @@ void PoolGroup<GameObject>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawn
                 ++itr;
 
                 // For dynamic spawns, save respawn time here
-                if (!go->GetRespawnCompatibilityMode())
+                if (saveRespawnTime && !go->GetRespawnCompatibilityMode())
                     go->SaveRespawnTime();
                 go->AddObjectToRemoveList();
             }
@@ -243,7 +243,7 @@ void PoolGroup<GameObject>::Despawn1Object(uint64 guid, bool alwaysDeleteRespawn
 
 // Same on one pool
 template<>
-void PoolGroup<Pool>::Despawn1Object(uint64 child_pool_id, bool alwaysDeleteRespawnTime)
+void PoolGroup<Pool>::Despawn1Object(uint64 child_pool_id, bool alwaysDeleteRespawnTime, bool /*saveRespawnTime*/)
 {
     sPoolMgr->DespawnPool(child_pool_id, alwaysDeleteRespawnTime);
 }
@@ -296,7 +296,7 @@ void PoolGroup<T>::SpawnObject(ActivePoolData& spawns, uint32 limit, uint64 trig
                 roll -= obj.chance;
                 // Triggering object is marked as spawned at this time and can be also rolled (respawn case)
                 // so this need explicit check for this case
-                if (roll < 0 && (/*obj.guid == triggerFrom ||*/ !spawns.IsActiveObject<T>(obj.guid)))
+                if (roll < 0 && (obj.guid == triggerFrom || !spawns.IsActiveObject<T>(obj.guid)))
                 {
                     rolledObjects.push_back(obj);
                     break;
@@ -306,9 +306,9 @@ void PoolGroup<T>::SpawnObject(ActivePoolData& spawns, uint32 limit, uint64 trig
 
         if (!EqualChanced.empty() && rolledObjects.empty())
         {
-            std::copy_if(EqualChanced.begin(), EqualChanced.end(), std::back_inserter(rolledObjects), [/*triggerFrom, */&spawns](PoolObject const& object)
+            std::copy_if(EqualChanced.begin(), EqualChanced.end(), std::back_inserter(rolledObjects), [triggerFrom, &spawns](PoolObject const& object)
             {
-                return /*object.guid == triggerFrom ||*/ !spawns.IsActiveObject<T>(object.guid);
+                return object.guid == triggerFrom || !spawns.IsActiveObject<T>(object.guid);
             });
 
             Trinity::Containers::RandomResize(rolledObjects, count);
@@ -385,16 +385,18 @@ void PoolGroup<Pool>::Spawn1Object(PoolObject* obj)
 
 // Method that does the respawn job on the specified creature
 template <>
-void PoolGroup<Creature>::ReSpawn1Object(PoolObject* /*obj*/)
+void PoolGroup<Creature>::ReSpawn1Object(PoolObject* obj)
 {
-    // Creature is still on map, nothing to do
+    Despawn1Object(obj->guid, false, false);
+    Spawn1Object(obj);
 }
 
 // Method that does the respawn job on the specified gameobject
 template <>
-void PoolGroup<GameObject>::ReSpawn1Object(PoolObject* /*obj*/)
+void PoolGroup<GameObject>::ReSpawn1Object(PoolObject* obj)
 {
-    // GameObject is still on map, nothing to do
+    Despawn1Object(obj->guid, false, false);
+    Spawn1Object(obj);
 }
 
 // Nothing to do for a child Pool
diff --git a/src/server/game/Pools/PoolMgr.h b/src/server/game/Pools/PoolMgr.h
index d8c9452caa2..5fb47f3deec 100644
--- a/src/server/game/Pools/PoolMgr.h
+++ b/src/server/game/Pools/PoolMgr.h
@@ -93,7 +93,7 @@ class TC_GAME_API PoolGroup
         void AddEntry(PoolObject& poolitem, uint32 maxentries);
         bool CheckPool() const;
         void DespawnObject(ActivePoolData& spawns, uint64 guid=0, bool alwaysDeleteRespawnTime = false);
-        void Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTime = false);
+        void Despawn1Object(uint64 guid, bool alwaysDeleteRespawnTime = false, bool saveRespawnTime = true);
         void SpawnObject(ActivePoolData& spawns, uint32 limit, uint64 triggerFrom);
         void RemoveRespawnTimeFromDB(uint64 guid);