2 files changed, 28 insertions, 5 deletions

diff --git a/src/Simulator/IncrementalRedstoneSimulator/DropSpenserHandler.h b/src/Simulator/IncrementalRedstoneSimulator/DropSpenserHandler.h
index b67b8d4fb..3c9952582 100644
--- a/src/Simulator/IncrementalRedstoneSimulator/DropSpenserHandler.h
+++ b/src/Simulator/IncrementalRedstoneSimulator/DropSpenserHandler.h
@@ -18,6 +18,22 @@ public:
 	{
 	}
 
+	inline static bool IsActivated(NIBBLETYPE a_Meta)
+	{
+		return (a_Meta & E_META_DROPSPENSER_ACTIVATED) != 0;
+	}
+	inline static NIBBLETYPE SetActivationState(NIBBLETYPE a_Meta, bool IsOn)
+	{
+		if (IsOn)
+		{
+			return a_Meta | E_META_DROPSPENSER_ACTIVATED;  // set the bit
+		}
+		else
+		{
+			return a_Meta & ~E_META_DROPSPENSER_ACTIVATED;  // clear the bit
+		}
+	}
+
 	virtual unsigned char GetPowerDeliveredToPosition(const Vector3i & a_Position, BLOCKTYPE a_BlockType, NIBBLETYPE a_Meta, const Vector3i & a_QueryPosition, BLOCKTYPE a_QueryBlockType) override
 	{
 		UNUSED(a_Position);
@@ -39,8 +55,9 @@ public:
 	virtual cVector3iArray Update(const Vector3i & a_Position, BLOCKTYPE a_BlockType, NIBBLETYPE a_Meta, PoweringData a_PoweringData) override
 	{
 		// LOGD("Evaluating spencer the dropspenser (%d %d %d)", a_Position.x, a_Position.y, a_Position.z);
-
-		if (a_PoweringData.PowerLevel > 0)
+		bool IsPoweredNow = (a_PoweringData.PowerLevel > 0);
+		bool WasPoweredPreviously = IsActivated(a_Meta);
+		if (IsPoweredNow && !WasPoweredPreviously)
 		{
 			class cSetPowerToDropSpenser :
 				public cDropSpenserCallback
@@ -56,6 +73,12 @@ public:
 			m_World.DoWithDropSpenserAt(a_Position.x, a_Position.y, a_Position.z, DrSpSP);
 		}
 
+		// Update the internal dropspenser state if necessary
+		if (IsPoweredNow != WasPoweredPreviously)
+		{
+			m_World.SetBlockMeta(a_Position, SetActivationState(a_Meta, IsPoweredNow));
+		}
+
 		return {};
 	}
 
diff --git a/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp b/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp
index 9f8c0f39d..c7be24dc4 100644
--- a/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp
+++ b/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp
@@ -196,12 +196,12 @@ void cIncrementalRedstoneSimulator::Simulate(float a_dt)
 		cRedstoneHandler::PoweringData Power;
 		for (const auto & Location : CurrentHandler->GetValidSourcePositions(CurrentLocation, CurrentBlock, CurrentMeta))
 		{
-			BLOCKTYPE PotentialBlock;
-			NIBBLETYPE PotentialMeta;
-			if ((Location.y < 0) || (Location.y > cChunkDef::Height))
+			if (!cChunk::IsValidHeight(Location.y))
 			{
 				continue;
 			}
+			BLOCKTYPE PotentialBlock;
+			NIBBLETYPE PotentialMeta;
 			m_World.GetBlockTypeMeta(Location.x, Location.y, Location.z, PotentialBlock, PotentialMeta);
 
 			auto PotentialSourceHandler = cIncrementalRedstoneSimulator::CreateComponent(m_World, PotentialBlock, &m_Data);