SpawnGroup: Attempt to remedy dungeon spawn group creature entry gen

src/game/Maps/SpawnGroup.cpp

@@ -240,10 +240,9 @@ void SpawnGroup::Spawn(bool force)
 
     std::shuffle(eligibleGuids.begin(), eligibleGuids.end(), *GetRandomGenerator());
 
-    for (auto itr = eligibleGuids.begin(); itr != eligibleGuids.end() && !eligibleGuids.empty() && m_objects.size() < m_entry.MaxCount; ++itr)
+    for (auto itr = eligibleGuids.begin(); itr != eligibleGuids.end() && !eligibleGuids.empty() && m_objects.size() < m_entry.MaxCount;)
     {
         uint32 dbGuid = (*itr)->DbGuid;
-        uint32 entry = 0;
         if (m_entry.HasChancedSpawns)
         {
             if ((*itr)->Chance)
@@ -259,44 +258,89 @@ void SpawnGroup::Spawn(bool force)
                     spawn = spawnItr->second;
 
                 if (!spawn)
+                {
+                    itr = eligibleGuids.erase(itr);
                     continue;
+                }
             }
             else // filling redundant entries when a group has chanced spawns for optimization so we can stop at start
                 m_chosenSpawns[dbGuid] = true;
+
+            ++itr;
         }
+    }
 
-        // creatures pick random entry on first spawn in dungeons - else always pick random entry
-        if (GetObjectTypeId() == TYPEID_UNIT)
+    eligibleGuids.resize(m_entry.MaxCount - m_objects.size()); // now we have final count for processing
+
+    auto pickCreatureEntry = [&](const SpawnGroupDbGuids* guids) -> uint32
+    {
+        uint32 entry;
+        // some group members can have static entry, or selfcontained random entry
+        if (guids->RandomEntry)
+            entry = sObjectMgr.GetRandomCreatureEntry(guids->DbGuid);
+        else if (guids->OwnEntry)
+            entry = guids->OwnEntry;
+        else
+            entry = GetEligibleEntry(validEntries, minEntries);
+
+        return entry;
+    };
+
+    auto pickGoEntry = [&](const SpawnGroupDbGuids* guids) -> uint32
+    {
+        uint32 entry;
+        // some group members can have static entry, or selfcontained random entry
+        if (guids->RandomEntry)
+            entry = sObjectMgr.GetRandomGameObjectEntry(guids->DbGuid);
+        else if (guids->OwnEntry)
+            entry = guids->OwnEntry;
+        else
+            entry = GetEligibleEntry(validEntries, minEntries);
+
+        return entry;
+    };
+
+    // pick static and random entry first in dungeons so spawn group logic can decide after
+    if (m_map.IsDungeon() && GetObjectTypeId() == TYPEID_UNIT)
+    {
+        for (auto data : eligibleGuids)
         {
-            if (m_map.IsDungeon())
+            if (data->RandomEntry || data->OwnEntry)
             {
-                // only held in memory - implement saving to db if it becomes a major issue
-                if (m_chosenEntries.find(dbGuid) == m_chosenEntries.end())
-                {
-                    // some group members can have static entry, or selfcontained random entry
-                    if ((*itr)->RandomEntry)
-                        entry = sObjectMgr.GetRandomCreatureEntry(dbGuid);
-                    else if ((*itr)->OwnEntry)
-                        entry = (*itr)->OwnEntry;
-                    else
-                        entry = GetEligibleEntry(validEntries, minEntries);
-                    m_chosenEntries[dbGuid] = entry;
-                }
-                else
-                    entry = m_chosenEntries[dbGuid];
+                uint32 entry = pickCreatureEntry(data);
+                m_chosenEntries[data->DbGuid] = entry;
+                if (entry && validEntries[entry])
+                    --validEntries[entry];
             }
-            else
-                entry = GetEligibleEntry(validEntries, minEntries);
         }
-        else // GOs always pick random entry
+        for (auto data : eligibleGuids)
         {
-            if ((*itr)->RandomEntry)
-                entry = sObjectMgr.GetRandomGameObjectEntry(dbGuid);
-            else if ((*itr)->OwnEntry)
-                entry = (*itr)->OwnEntry;
-            else
-                entry = GetEligibleEntry(validEntries, minEntries);
+            if (!data->RandomEntry && !data->OwnEntry)
+            {
+                uint32 entry = pickCreatureEntry(data);
+                m_chosenEntries[data->DbGuid] = entry;
+                if (entry && validEntries[entry])
+                    --validEntries[entry];
+            }
         }
+    }
+
+    for (auto itr = eligibleGuids.begin(); itr != eligibleGuids.end(); ++itr)
+    {
+        uint32 dbGuid = (*itr)->DbGuid;
+        uint32 entry = 0;
+        // creatures pick random entry on first spawn in dungeons - else always pick random entry
+        if (m_map.IsDungeon() && GetObjectTypeId() == TYPEID_UNIT)
+            entry = m_chosenEntries[dbGuid]; // only held in memory - implement saving to db if it becomes a major issue
+        else
+        {
+            if (GetObjectTypeId() == TYPEID_UNIT)
+                entry = pickCreatureEntry(*itr);
+            else // GOs always pick random entry
+                entry = pickGoEntry(*itr);
+            if (entry && validEntries[entry])
+                --validEntries[entry];
+        }   
 
         float x, y;
         if (GetObjectTypeId() == TYPEID_UNIT)
@@ -319,8 +363,6 @@ void SpawnGroup::Spawn(bool force)
             else
                 WorldObject::SpawnGameObject(dbGuid, &m_map, entry);
         }
-        if (entry && validEntries[entry])
-            --validEntries[entry];
     }
 }