2 files changed, 16 insertions, 0 deletions
diff --git a/src/server/game/Instances/InstanceScript.cpp b/src/server/game/Instances/InstanceScript.cpp
index fd3d16a2772..2494c4852af 100644
--- a/src/server/game/Instances/InstanceScript.cpp
+++ b/src/server/game/Instances/InstanceScript.cpp
@@ -477,6 +477,12 @@ void InstanceScript::Load(char const* data)
     InstanceScriptDataReader reader(*this);
     if (reader.Load(data) == InstanceScriptDataReader::Result::Ok)
     {
+        // in loot-based lockouts instance can be loaded with later boss marked as killed without preceding bosses
+        // but we still need to have them alive
+        for (uint32 i = 0; i < bosses.size(); ++i)
+            if (bosses[i].state == DONE && !CheckRequiredBosses(i))
+                bosses[i].state = NOT_STARTED;
+
         UpdateSpawnGroups();
         AfterDataLoad();
     }
@@ -740,6 +746,15 @@ bool InstanceScript::IsEncounterCompleted(uint32 dungeonEncounterId) const
     return false;
 }
 
+bool InstanceScript::IsEncounterCompletedInMaskByBossId(uint32 completedEncountersMask, uint32 bossId) const
+{
+    if (DungeonEncounterEntry const* dungeonEncounter = GetBossDungeonEncounter(bossId))
+        if (completedEncountersMask & (1 << dungeonEncounter->Bit))
+            return bosses[bossId].state == DONE;
+
+    return false;
+}
+
 void InstanceScript::SetEntranceLocation(uint32 worldSafeLocationId)
 {
     _entranceId = worldSafeLocationId;
diff --git a/src/server/game/Instances/InstanceScript.h b/src/server/game/Instances/InstanceScript.h
index b7a2e2fc15e..0e44521dcb0 100644
--- a/src/server/game/Instances/InstanceScript.h
+++ b/src/server/game/Instances/InstanceScript.h
@@ -287,6 +287,7 @@ class TC_GAME_API InstanceScript : public ZoneScript
         uint32 GetCompletedEncounterMask() const { return completedEncounters; }
 
         bool IsEncounterCompleted(uint32 dungeonEncounterId) const;
+        bool IsEncounterCompletedInMaskByBossId(uint32 completedEncountersMask, uint32 bossId) const;
 
         uint32 GetEncounterCount() const { return uint32(bosses.size()); }