[7299] Implemented circular loop detection for pools in pools

As a result, the last relation that makes the loop is automatically removed.
An error message is displayed and core go on loading remaining records.

Signed-off-by: Neo2003 <neo.2003@hotmail.fr>

src/game/PoolHandler.cpp

@@ -270,6 +270,30 @@ void PoolHandler::LoadFromDB()
             mPoolSearchMap.insert(p);
 
         } while( result->NextRow() );
+
+        // Now check for circular reference
+        for(uint16 i=0; i<max_pool_id; ++i)
+        {
+            std::set<uint16> checkedPools;
+            for(SearchMap::iterator poolItr = mPoolSearchMap.find(i); poolItr != mPoolSearchMap.end(); poolItr = mPoolSearchMap.find(poolItr->second))
+            {
+                checkedPools.insert(poolItr->first);
+                if(checkedPools.find(poolItr->second) != checkedPools.end())
+                {
+                    std::ostringstream ss;
+                    ss<< "The pool(s) ";
+                    for (std::set<uint16>::const_iterator itr=checkedPools.begin(); itr!=checkedPools.end(); ++itr)
+                        ss << *itr << " ";
+                    ss << "create(s) a circular reference, which can cause the server to freeze.\nRemoving the last link between mother pool "
+                        << poolItr->first << " and child pool " << poolItr->second;
+                    sLog.outErrorDb(ss.str().c_str());
+                    mPoolPoolGroups[poolItr->second].RemoveOneRelation(poolItr->first);
+                    mPoolSearchMap.erase(poolItr);
+                    --count;
+                    break;
+                }
+            }
+        }
         sLog.outString();
         sLog.outString( ">> Loaded %u pools in mother pools", count );
         delete result;
@@ -518,6 +542,28 @@ void PoolHandler::PoolGroup<PoolHandler::Pool>::Despawn1Object(uint32 child_pool
     poolhandler.DespawnPool(child_pool_id);
 }
 
+// Method for a pool only to remove any found record causing a circular dependency loop
+template<>
+void PoolHandler::PoolGroup<PoolHandler::Pool>::RemoveOneRelation(uint16 child_pool_id)
+{
+    for (PoolObjectList::iterator itr = ExplicitlyChanced.begin(); itr != ExplicitlyChanced.end(); ++itr)
+    {
+        if(itr->guid == child_pool_id)
+        {
+            ExplicitlyChanced.erase(itr);
+            break;
+        }
+    }
+    for (PoolObjectList::iterator itr = EqualChanced.begin(); itr != EqualChanced.end(); ++itr)
+    {
+        if(itr->guid == child_pool_id)
+        {
+            EqualChanced.erase(itr);
+            break;
+        }
+    }
+}
+
 // Method that Spawn 1+ creatures or gameobject
 // if cache is false (initialization or event start), X creatures are spawned with X <= limit (< if limit higher that the number of creatures in pool)
 // if cache is true, this means only one has to be spawned (or respawned if the rolled one is same as cached one)

src/game/PoolHandler.h

@@ -91,6 +91,7 @@ class PoolHandler::PoolGroup
         void SpawnObject(uint32 limit, bool cache=false);
         bool Spawn1Object(uint32 guid);
         bool ReSpawn1Object(uint32 guid);
+        void RemoveOneRelation(uint16 child_pool_id);
     private:
         typedef std::vector<PoolObject> PoolObjectList;
         uint32 CacheValue;                                      // Store the guid of the removed creature/gameobject during a pool update

src/shared/revision_nr.h

@@ -1,4 +1,4 @@
 #ifndef __REVISION_NR_H__
 #define __REVISION_NR_H__
- #define REVISION_NR "7298"
+ #define REVISION_NR "7299"
 #endif // __REVISION_NR_H__