Core/Dungeon finder: Fix teleport out after dungeon is finished

Closes 8914

src/server/game/DungeonFinding/LFGMgr.cpp

@@ -1563,7 +1563,6 @@ void LFGMgr::FinishDungeon(uint64 gguid, const uint32 dungeonId)
         LfgPlayerRewardData data = LfgPlayerRewardData(dungeon->Entry(), GetDungeon(gguid, false), done, quest);
         player->GetSession()->SendLfgPlayerReward(data);
     }
-    SetDungeon(gguid, 0);
 }
 
 // --------------------------------------------------------------------------//
@@ -1632,6 +1631,18 @@ LfgState LFGMgr::GetState(uint64 guid)
     return state;
 }
 
+LfgState LFGMgr::GetOldState(uint64 guid)
+{
+    LfgState state;
+    if (IS_GROUP_GUID(guid))
+        state = GroupsStore[guid].GetOldState();
+    else
+        state = PlayersStore[guid].GetOldState();
+
+    sLog->outTrace(LOG_FILTER_LFG, "LFGMgr::GetOldState: [" UI64FMTD "] = %u", guid, state);
+    return state;
+}
+
 uint32 LFGMgr::GetDungeon(uint64 guid, bool asId /*= true */)
 {
     uint32 dungeon = GroupsStore[guid].GetDungeon(asId);

src/server/game/DungeonFinding/LFGMgr.h

@@ -347,6 +347,7 @@ class LFGMgr
         uint32 GetDungeon(uint64 guid, bool asId = true);
         uint32 GetDungeonMapId(uint64 guid);
         LfgState GetState(uint64 guid);
+        LfgState GetOldState(uint64 guid);
         uint8 GetKicksLeft(uint64 gguid);
         uint64 GetLeader(uint64 guid);
         bool IsLfgGroup(uint64 guid);

src/server/game/DungeonFinding/LFGQueue.cpp

@@ -483,7 +483,7 @@ LfgCompatibility LFGQueue::CheckCompatibility(LfgGuidList check)
 
     uint64 gguid = *check.begin();
     proposal.queues = check;
-    proposal.isNew = numLfgGroups != 1 || !sLFGMgr->GetDungeon(gguid);
+    proposal.isNew = numLfgGroups != 1 || sLFGMgr->GetOldState(gguid) != LFG_STATE_DUNGEON;
 
     if (!sLFGMgr->AllQueued(check))
     {