14 files changed, 400 insertions, 161 deletions

diff --git a/MCServer/Plugins/APIDump/APIDesc.lua b/MCServer/Plugins/APIDump/APIDesc.lua
index aa818fc11..0e626c580 100644
--- a/MCServer/Plugins/APIDump/APIDesc.lua
+++ b/MCServer/Plugins/APIDump/APIDesc.lua
@@ -2343,6 +2343,7 @@ end
 					{ Params = "BlockX, BlockY, BlockZ, BlockMeta", Return = "", Notes = "Sets the meta for the block at the specified coords." },
 					{ Params = "{{Vector3i|BlockCoords}}, BlockMeta", Return = "", Notes = "Sets the meta for the block at the specified coords." },
 				},
+				SetChunkAlwaysTicked = { Params = "ChunkX, ChunkZ, IsAlwaysTicked", Return = "", Notes = "Sets the chunk to always be ticked even when it doesn't contain any clients. IsAlwaysTicked set to true turns forced ticking on, set to false turns it off. Every call with 'true' should be paired with a later call with 'false', otherwise the ticking won't stop. Multiple actions can request ticking independently, the ticking will continue until the last call with 'false'. Note that when the chunk unloads, it loses the value of this flag." },
 				SetNextBlockTick = { Params = "BlockX, BlockY, BlockZ", Return = "", Notes = "Sets the blockticking to start at the specified block in the next tick." },
 				SetCommandBlockCommand = { Params = "BlockX, BlockY, BlockZ, Command", Return = "bool", Notes = "Sets the command to be executed in a command block at the specified coordinates. Returns if command was changed." },
 				SetCommandBlocksEnabled = { Params = "IsEnabled (bool)", Return = "", Notes = "Sets whether command blocks should be enabled on the (entire) server." },
diff --git a/MCServer/Plugins/Debuggers/Debuggers.lua b/MCServer/Plugins/Debuggers/Debuggers.lua
index deb6a720b..918204deb 100644
--- a/MCServer/Plugins/Debuggers/Debuggers.lua
+++ b/MCServer/Plugins/Debuggers/Debuggers.lua
@@ -31,6 +31,8 @@ function Initialize(Plugin)
 	PM:AddHook(cPluginManager.HOOK_PLUGIN_MESSAGE,               OnPluginMessage);
 	PM:AddHook(cPluginManager.HOOK_PLAYER_JOINED,                OnPlayerJoined);
 	PM:AddHook(cPluginManager.HOOK_PROJECTILE_HIT_BLOCK,         OnProjectileHitBlock);
+	PM:AddHook(cPluginManager.HOOK_CHUNK_UNLOADING,              OnChunkUnloading);
+	PM:AddHook(cPluginManager.HOOK_WORLD_STARTED,                OnWorldStarted);
 
 	-- _X: Disabled so that the normal operation doesn't interfere with anything
 	-- PM:AddHook(cPluginManager.HOOK_CHUNK_GENERATED,              OnChunkGenerated);
@@ -1382,6 +1384,7 @@ end
 
 
 function OnProjectileHitBlock(a_Projectile, a_BlockX, a_BlockY, a_BlockZ, a_BlockFace, a_BlockHitPos)
+	-- Test projectile hooks by setting the blocks they hit on fire:
 	local BlockX, BlockY, BlockZ = AddFaceDirection(a_BlockX, a_BlockY, a_BlockZ, a_BlockFace)
 	local World = a_Projectile:GetWorld()
 	
@@ -1391,3 +1394,28 @@ end
 
 
 
+
+function OnChunkUnloading(a_World, a_ChunkX, a_ChunkZ)
+	-- Do not let chunk [0, 0] unload, so that it continues ticking [cWorld:SetChunkAlwaysTicked() test]
+	if ((a_ChunkX == 0) and (a_ChunkZ == 0)) then
+		return true
+	end
+end
+
+
+
+
+
+function OnWorldStarted(a_World)
+	-- Make the chunk [0, 0] in every world keep ticking [cWorld:SetChunkAlwaysTicked() test]
+	a_World:ChunkStay({{0, 0}}, nil,
+		function()
+			-- The chunk is loaded, make it always tick:
+			a_World:SetChunkAlwaysTicked(0, 0, true)
+		end
+	)
+end
+
+
+
+
diff --git a/src/Chunk.cpp b/src/Chunk.cpp
index 0fee40cac..1e80eb61b 100644
--- a/src/Chunk.cpp
+++ b/src/Chunk.cpp
@@ -87,7 +87,8 @@ cChunk::cChunk(
 	m_NeighborZM(a_NeighborZM),
 	m_NeighborZP(a_NeighborZP),
 	m_WaterSimulatorData(a_World->GetWaterSimulator()->CreateChunkData()),
-	m_LavaSimulatorData (a_World->GetLavaSimulator ()->CreateChunkData())
+	m_LavaSimulatorData (a_World->GetLavaSimulator ()->CreateChunkData()),
+	m_AlwaysTicked(0)
 {
 	if (a_NeighborXM != NULL)
 	{
@@ -463,7 +464,7 @@ void cChunk::CollectMobCensus(cMobCensus& toFill)
 
 
 
-void cChunk::getThreeRandomNumber(int& a_X, int& a_Y, int& a_Z,int a_MaxX, int a_MaxY, int a_MaxZ)
+void cChunk::GetThreeRandomNumbers(int & a_X, int & a_Y, int & a_Z,int a_MaxX, int a_MaxY, int a_MaxZ)
 {
 	ASSERT(a_MaxX * a_MaxY * a_MaxZ * 8 < 0x00ffffff);
 	int Random = m_World->GetTickRandomNumber(0x00ffffff);
@@ -479,12 +480,12 @@ void cChunk::getThreeRandomNumber(int& a_X, int& a_Y, int& a_Z,int a_MaxX, int a
 
 
 
-void cChunk::getRandomBlockCoords(int& a_X, int& a_Y, int& a_Z)
+void cChunk::GetRandomBlockCoords(int & a_X, int & a_Y, int & a_Z)
 {
 	// MG TODO : check if this kind of optimization (only one random call) is still needed
 	// MG TODO : if so propagate it
 
-	getThreeRandomNumber(a_X, a_Y, a_Z, Width, Height-2, Width);
+	GetThreeRandomNumbers(a_X, a_Y, a_Z, Width, Height - 2, Width);
 	a_Y++;
 }
 
@@ -494,65 +495,68 @@ void cChunk::getRandomBlockCoords(int& a_X, int& a_Y, int& a_Z)
 
 void cChunk::SpawnMobs(cMobSpawner& a_MobSpawner)
 {
-	int Center_X,Center_Y,Center_Z;
-	getRandomBlockCoords(Center_X,Center_Y,Center_Z);
-
-	BLOCKTYPE PackCenterBlock = GetBlock(Center_X, Center_Y, Center_Z);
-	if (a_MobSpawner.CheckPackCenter(PackCenterBlock))
-	{
-		a_MobSpawner.NewPack();
-		int NumberOfTries = 0;
-		int NumberOfSuccess = 0;
-		int MaxNbOfSuccess = 4; // this can be changed during the process for Wolves and Ghass
-		while (NumberOfTries < 12 && NumberOfSuccess < MaxNbOfSuccess)
-		{
-			const int HorizontalRange = 20; // MG TODO : relocate
-			const int VerticalRange = 0; // MG TODO : relocate
-			int Try_X, Try_Y, Try_Z;
-			getThreeRandomNumber(Try_X, Try_Y, Try_Z, 2*HorizontalRange+1 , 2*VerticalRange+1 , 2*HorizontalRange+1);
-			Try_X -= HorizontalRange;
-			Try_Y -= VerticalRange;
-			Try_Z -= HorizontalRange;
-			Try_X += Center_X;
-			Try_Y += Center_Y;
-			Try_Z += Center_Z;
-
-			ASSERT(Try_Y > 0);
-			ASSERT(Try_Y < cChunkDef::Height-1);
-			
-			EMCSBiome Biome = m_ChunkMap->GetBiomeAt (Try_X, Try_Z);
-			// MG TODO :
-			// Moon cycle (for slime)
-			// check player and playerspawn presence < 24 blocks
-			// check mobs presence on the block
-
-			// MG TODO : check that "Level" really means Y
-			
-			/*
-			NIBBLETYPE SkyLight = 0;
-
-			NIBBLETYPE BlockLight = 0;
-			*/
+	int CenterX, CenterY, CenterZ;
+	GetRandomBlockCoords(CenterX, CenterY, CenterZ);
 
-			if (IsLightValid())
-			{
-				cEntity* newMob = a_MobSpawner.TryToSpawnHere(this, Try_X, Try_Y, Try_Z, Biome, MaxNbOfSuccess);
-				if (newMob)
-				{
-					int WorldX, WorldY, WorldZ;
-					PositionToWorldPosition(Try_X, Try_Y, Try_Z, WorldX, WorldY, WorldZ);
-					double ActualX = WorldX + 0.5;
-					double ActualZ = WorldZ + 0.5;
-					newMob->SetPosition(ActualX, WorldY, ActualZ);
-					LOGD("Spawning %s #%i at %d,%d,%d",newMob->GetClass(),newMob->GetUniqueID(),WorldX, WorldY, WorldZ);
-					NumberOfSuccess++;
-				}
-			}
-			
-			NumberOfTries++;
-		}
+	BLOCKTYPE PackCenterBlock = GetBlock(CenterX, CenterY, CenterZ);
+	if (!a_MobSpawner.CheckPackCenter(PackCenterBlock))
+	{
+		return;
 	}
+	
+	a_MobSpawner.NewPack();
+	int NumberOfTries = 0;
+	int NumberOfSuccess = 0;
+	int MaxNbOfSuccess = 4;  // This can be changed during the process for Wolves and Ghasts
+	while ((NumberOfTries < 12) && (NumberOfSuccess < MaxNbOfSuccess))
+	{
+		const int HorizontalRange = 20;  // MG TODO : relocate
+		const int VerticalRange = 0;     // MG TODO : relocate
+		int TryX, TryY, TryZ;
+		GetThreeRandomNumbers(TryX, TryY, TryZ, 2 * HorizontalRange + 1, 2 * VerticalRange + 1, 2 * HorizontalRange + 1);
+		TryX -= HorizontalRange;
+		TryY -= VerticalRange;
+		TryZ -= HorizontalRange;
+		TryX += CenterX;
+		TryY += CenterY;
+		TryZ += CenterZ;
+
+		ASSERT(TryY > 0);
+		ASSERT(TryY < cChunkDef::Height - 1);
+		
+		EMCSBiome Biome = m_ChunkMap->GetBiomeAt(TryX, TryZ);
+		// MG TODO :
+		// Moon cycle (for slime)
+		// check player and playerspawn presence < 24 blocks
+		// check mobs presence on the block
+
+		// MG TODO : check that "Level" really means Y
+		
+		/*
+		NIBBLETYPE SkyLight = 0;
+
+		NIBBLETYPE BlockLight = 0;
+		*/
 
+		NumberOfTries++;
+		if (!IsLightValid())
+		{
+			continue;
+		}
+		
+		cEntity * newMob = a_MobSpawner.TryToSpawnHere(this, TryX, TryY, TryZ, Biome, MaxNbOfSuccess);
+		if (newMob == NULL)
+		{
+			continue;
+		}
+		int WorldX, WorldY, WorldZ;
+		PositionToWorldPosition(TryX, TryY, TryZ, WorldX, WorldY, WorldZ);
+		double ActualX = WorldX + 0.5;
+		double ActualZ = WorldZ + 0.5;
+		newMob->SetPosition(ActualX, WorldY, ActualZ);
+		LOGD("Spawning %s #%i at {%d, %d, %d}", newMob->GetClass(), newMob->GetUniqueID(), WorldX, WorldY, WorldZ);
+		NumberOfSuccess++;
+	}  // while (retry)
 }
 
 
@@ -1641,6 +1645,31 @@ cBlockEntity * cChunk::GetBlockEntity(int a_BlockX, int a_BlockY, int a_BlockZ)
 
 
 
+bool cChunk::ShouldBeTicked(void) const
+{
+	return (HasAnyClients() || (m_AlwaysTicked > 0));
+}
+
+
+
+
+
+void cChunk::SetAlwaysTicked(bool a_AlwaysTicked)
+{
+	if (a_AlwaysTicked)
+	{
+		m_AlwaysTicked += 1;
+	}
+	else
+	{
+		m_AlwaysTicked -= 1;
+	}
+}
+
+
+
+
+
 void cChunk::UseBlockEntity(cPlayer * a_Player, int a_X, int a_Y, int a_Z)
 {
 	cBlockEntity * be = GetBlockEntity(a_X, a_Y, a_Z);
@@ -1852,7 +1881,7 @@ bool cChunk::HasClient( cClientHandle* a_Client )
 
 
 
-bool cChunk::HasAnyClients(void)
+bool cChunk::HasAnyClients(void) const
 {
 	return !m_LoadedByClient.empty();
 }
diff --git a/src/Chunk.h b/src/Chunk.h
index e9d964e05..90664b513 100644
--- a/src/Chunk.h
+++ b/src/Chunk.h
@@ -200,11 +200,16 @@ public:
 	void SendBlockTo(int a_RelX, int a_RelY, int a_RelZ, cClientHandle * a_Client);
 
 	/** Adds a client to the chunk; returns true if added, false if already there */
-	bool AddClient    (cClientHandle* a_Client );
+	bool AddClient(cClientHandle * a_Client);
 	
-	void RemoveClient (cClientHandle* a_Client );
-	bool HasClient    (cClientHandle* a_Client );
-	bool HasAnyClients(void);  // Returns true if theres any client in the chunk; false otherwise
+	/** Removes the specified client from the chunk; ignored if client not in chunk. */
+	void RemoveClient(cClientHandle * a_Client);
+	
+	/** Returns true if the specified client is present in this chunk. */
+	bool HasClient(cClientHandle * a_Client);
+	
+	/** Returns true if theres any client in the chunk; false otherwise */
+	bool HasAnyClients(void) const;
 
 	void AddEntity(cEntity * a_Entity);
 	void RemoveEntity(cEntity * a_Entity);
@@ -390,6 +395,17 @@ public:
 
 	cBlockEntity * GetBlockEntity(int a_BlockX, int a_BlockY, int a_BlockZ);
 	cBlockEntity * GetBlockEntity(const Vector3i & a_BlockPos) { return GetBlockEntity(a_BlockPos.x, a_BlockPos.y, a_BlockPos.z); }
+	
+	/** Returns true if the chunk should be ticked in the tick-thread.
+	Checks if there are any clients and if the always-tick flag is set */
+	bool ShouldBeTicked(void) const;
+	
+	/** Increments (a_AlwaysTicked == true) or decrements (false) the m_AlwaysTicked counter.
+	If the m_AlwaysTicked counter is greater than zero, the chunk is ticked in the tick-thread regardless of
+	whether it has any clients or not.
+	This function allows nesting and task-concurrency (multiple separate tasks can request ticking and as long
+	as at least one requests is active the chunk will be ticked). */
+	void SetAlwaysTicked(bool a_AlwaysTicked);
 
 private:
 
@@ -462,10 +478,16 @@ private:
 
 	/** Indicates if simulate-once blocks should be updated by the redstone simulator */
 	bool m_IsRedstoneDirty;
+	
+	/** If greater than zero, the chunk is ticked even if it has no clients.
+	Manipulated by the SetAlwaysTicked() function, allows for nested calls of the function.
+	This is the support for plugin-accessible chunk tick forcing. */
+	int m_AlwaysTicked;
+	
 
 	// Pick up a random block of this chunk
-	void getRandomBlockCoords(int& a_X, int& a_Y, int& a_Z);
-	void getThreeRandomNumber(int& a_X, int& a_Y, int& a_Z,int a_MaxX, int a_MaxY, int a_MaxZ);
+	void GetRandomBlockCoords(int & a_X, int & a_Y, int & a_Z);
+	void GetThreeRandomNumbers(int & a_X, int & a_Y, int & a_Z, int a_MaxX, int a_MaxY, int a_MaxZ);
 
 	void RemoveBlockEntity(cBlockEntity * a_BlockEntity);
 	void AddBlockEntity   (cBlockEntity * a_BlockEntity);
diff --git a/src/ChunkMap.cpp b/src/ChunkMap.cpp
index c9fb0b59e..687c0824f 100644
--- a/src/ChunkMap.cpp
+++ b/src/ChunkMap.cpp
@@ -2674,6 +2674,20 @@ void cChunkMap::QueueTickBlock(int a_BlockX, int a_BlockY, int a_BlockZ)
 
 
 
+void cChunkMap::SetChunkAlwaysTicked(int a_ChunkX, int a_ChunkZ, bool a_AlwaysTicked)
+{
+	cCSLock Lock(m_CSLayers);
+	cChunkPtr Chunk = GetChunkNoLoad(a_ChunkX, ZERO_CHUNK_Y, a_ChunkZ);
+	if (Chunk != NULL)
+	{
+		Chunk->SetAlwaysTicked(a_AlwaysTicked);
+	}
+}
+
+
+
+
+
 ////////////////////////////////////////////////////////////////////////////////
 // cChunkMap::cChunkLayer:
 
@@ -2788,12 +2802,14 @@ void cChunkMap::cChunkLayer::SpawnMobs(cMobSpawner& a_MobSpawner)
 
 
 
+
+
 void cChunkMap::cChunkLayer::Tick(float a_Dt)
 {
 	for (size_t i = 0; i < ARRAYCOUNT(m_Chunks); i++)
 	{
-		// Only tick chunks that are valid and have clients:
-		if ((m_Chunks[i] != NULL) && m_Chunks[i]->IsValid() && m_Chunks[i]->HasAnyClients())
+		// Only tick chunks that are valid and should be ticked:
+		if ((m_Chunks[i] != NULL) && m_Chunks[i]->IsValid() && m_Chunks[i]->ShouldBeTicked())
 		{
 			m_Chunks[i]->Tick(a_Dt);
 		}
diff --git a/src/ChunkMap.h b/src/ChunkMap.h
index 433516490..b8870dfca 100644
--- a/src/ChunkMap.h
+++ b/src/ChunkMap.h
@@ -339,6 +339,13 @@ public:
 	
 	/** Returns the CS for locking the chunkmap; only cWorld::cLock may use this function! */
 	cCriticalSection & GetCS(void) { return m_CSLayers; }
+	
+	/** Increments (a_AlwaysTicked == true) or decrements (false) the m_AlwaysTicked counter for the specified chunk.
+	If the m_AlwaysTicked counter is greater than zero, the chunk is ticked in the tick-thread regardless of
+	whether it has any clients or not.
+	This function allows nesting and task-concurrency (multiple separate tasks can request ticking and as long
+	as at least one requests is active the chunk will be ticked). */
+	void SetChunkAlwaysTicked(int a_ChunkX, int a_ChunkZ, bool a_AlwaysTicked);
 
 private:
 
diff --git a/src/Entities/Player.cpp b/src/Entities/Player.cpp
index cc07c25a8..baa3fe7f6 100644
--- a/src/Entities/Player.cpp
+++ b/src/Entities/Player.cpp
@@ -34,51 +34,47 @@
 
 
 
-cPlayer::cPlayer(cClientHandle* a_Client, const AString & a_PlayerName)
-	: super(etPlayer, 0.6, 1.8)
-	, m_bVisible(true)
-	, m_FoodLevel(MAX_FOOD_LEVEL)
-	, m_FoodSaturationLevel(5.0)
-	, m_FoodTickTimer(0)
-	, m_FoodExhaustionLevel(0.0)
-	, m_LastJumpHeight(0)
-	, m_LastGroundHeight(0)
-	, m_bTouchGround(false)
-	, m_Stance(0.0)
-	, m_Inventory(*this)
-	, m_EnderChestContents(9, 3)
-	, m_CurrentWindow(NULL)
-	, m_InventoryWindow(NULL)
-	, m_Color('-')
-	, m_GameMode(eGameMode_NotSet)
-	, m_IP("")
-	, m_ClientHandle(a_Client)
-	, m_NormalMaxSpeed(1.0)
-	, m_SprintingMaxSpeed(1.3)
-	, m_FlyingMaxSpeed(1.0)
-	, m_IsCrouched(false)
-	, m_IsSprinting(false)
-	, m_IsFlying(false)
-	, m_IsSwimming(false)
-	, m_IsSubmerged(false)
-	, m_IsFishing(false)
-	, m_CanFly(false)
-	, m_EatingFinishTick(-1)
-	, m_LifetimeTotalXp(0)
-	, m_CurrentXp(0)
-	, m_bDirtyExperience(false)
-	, m_IsChargingBow(false)
-	, m_BowCharge(0)
-	, m_FloaterID(-1)
-	, m_Team(NULL)
-	, m_TicksUntilNextSave(PLAYER_INVENTORY_SAVE_INTERVAL)
-	, m_bIsTeleporting(false)
-{
-	LOGD("Created a player object for \"%s\" @ \"%s\" at %p, ID %d", 
-		a_PlayerName.c_str(), a_Client->GetIPString().c_str(),
-		this, GetUniqueID()
-	);
-	
+cPlayer::cPlayer(cClientHandle* a_Client, const AString & a_PlayerName) :
+	super(etPlayer, 0.6, 1.8),
+	m_bVisible(true),
+	m_FoodLevel(MAX_FOOD_LEVEL),
+	m_FoodSaturationLevel(5.0),
+	m_FoodTickTimer(0),
+	m_FoodExhaustionLevel(0.0),
+	m_LastJumpHeight(0),
+	m_LastGroundHeight(0),
+	m_bTouchGround(false),
+	m_Stance(0.0),
+	m_Inventory(*this),
+	m_EnderChestContents(9, 3),
+	m_CurrentWindow(NULL),
+	m_InventoryWindow(NULL),
+	m_Color('-'),
+	m_GameMode(eGameMode_NotSet),
+	m_IP(""),
+	m_ClientHandle(a_Client),
+	m_NormalMaxSpeed(1.0),
+	m_SprintingMaxSpeed(1.3),
+	m_FlyingMaxSpeed(1.0),
+	m_IsCrouched(false),
+	m_IsSprinting(false),
+	m_IsFlying(false),
+	m_IsSwimming(false),
+	m_IsSubmerged(false),
+	m_IsFishing(false),
+	m_CanFly(false),
+	m_EatingFinishTick(-1),
+	m_LifetimeTotalXp(0),
+	m_CurrentXp(0),
+	m_bDirtyExperience(false),
+	m_IsChargingBow(false),
+	m_BowCharge(0),
+	m_FloaterID(-1),
+	m_Team(NULL),
+	m_TicksUntilNextSave(PLAYER_INVENTORY_SAVE_INTERVAL),
+	m_bIsTeleporting(false),
+	m_UUID((a_Client != NULL) ? a_Client->GetUUID() : "")
+{
 	m_InventoryWindow = new cInventoryWindow(*this);
 	m_CurrentWindow = m_InventoryWindow;
 	m_InventoryWindow->OpenedByPlayer(*this);
@@ -1670,53 +1666,98 @@ void cPlayer::LoadPermissionsFromDisk()
 
 
 
-bool cPlayer::LoadFromDisk()
+
+bool cPlayer::LoadFromDisk(void)
 {
 	LoadPermissionsFromDisk();
 
-	AString SourceFile;
-	Printf(SourceFile, "players/%s.json", GetName().c_str() );
+	// Load from the UUID file:
+	if (LoadFromFile(GetUUIDFileName(m_UUID)))
+	{
+		return true;
+	}
+	
+	// Load from the offline UUID file, if allowed:
+	AString OfflineUUID = cClientHandle::GenerateOfflineUUID(GetName());
+	if (cRoot::Get()->GetServer()->ShouldLoadOfflinePlayerData())
+	{
+		if (LoadFromFile(GetUUIDFileName(OfflineUUID)))
+		{
+			return true;
+		}
+	}
+	
+	// Load from the old-style name-based file, if allowed:
+	if (cRoot::Get()->GetServer()->ShouldLoadNamedPlayerData())
+	{
+		AString OldStyleFileName = Printf("players/%s.json", GetName().c_str());
+		if (LoadFromFile(OldStyleFileName))
+		{
+			// Save in new format and remove the old file
+			if (SaveToDisk())
+			{
+				cFile::Delete(OldStyleFileName);
+			}
+			return true;
+		}
+	}
+	
+	// None of the files loaded successfully
+	LOG("Player data file not found for %s (%s, offline %s), will be reset to defaults.",
+		GetName().c_str(), m_UUID.c_str(), OfflineUUID.c_str()
+	);
+	return false;
+}
+
+
+
+
 
+bool cPlayer::LoadFromFile(const AString & a_FileName)
+{
+	// Load the data from the file:
 	cFile f;
-	if (!f.Open(SourceFile, cFile::fmRead))
+	if (!f.Open(a_FileName, cFile::fmRead))
 	{
 		// This is a new player whom we haven't seen yet, bail out, let them have the defaults
 		return false;
 	}
-
 	AString buffer;
 	if (f.ReadRestOfFile(buffer) != f.GetSize())
 	{
-		LOGWARNING("Cannot read player data from file \"%s\"", SourceFile.c_str()); 
+		LOGWARNING("Cannot read player data from file \"%s\"", a_FileName.c_str());
 		return false;
 	}
-	f.Close(); //cool kids play nice
+	f.Close();
 
+	// Parse the JSON format:
 	Json::Value root;
 	Json::Reader reader;
 	if (!reader.parse(buffer, root, false))
 	{
-		LOGWARNING("Cannot parse player data in file \"%s\", player will be reset", SourceFile.c_str());
+		LOGWARNING("Cannot parse player data in file \"%s\"", a_FileName.c_str());
+		return false;
 	}
 
+	// Load the player data:
 	Json::Value & JSON_PlayerPosition = root["position"];
 	if (JSON_PlayerPosition.size() == 3)
 	{
-		SetPosX(JSON_PlayerPosition[(unsigned int)0].asDouble());
-		SetPosY(JSON_PlayerPosition[(unsigned int)1].asDouble());
-		SetPosZ(JSON_PlayerPosition[(unsigned int)2].asDouble());
+		SetPosX(JSON_PlayerPosition[(unsigned)0].asDouble());
+		SetPosY(JSON_PlayerPosition[(unsigned)1].asDouble());
+		SetPosZ(JSON_PlayerPosition[(unsigned)2].asDouble());
 		m_LastPos = GetPosition();
 	}
 
 	Json::Value & JSON_PlayerRotation = root["rotation"];
 	if (JSON_PlayerRotation.size() == 3)
 	{
-		SetYaw      ((float)JSON_PlayerRotation[(unsigned int)0].asDouble());
-		SetPitch    ((float)JSON_PlayerRotation[(unsigned int)1].asDouble());
-		SetRoll     ((float)JSON_PlayerRotation[(unsigned int)2].asDouble());
+		SetYaw      ((float)JSON_PlayerRotation[(unsigned)0].asDouble());
+		SetPitch    ((float)JSON_PlayerRotation[(unsigned)1].asDouble());
+		SetRoll     ((float)JSON_PlayerRotation[(unsigned)2].asDouble());
 	}
 
-	m_Health              = root.get("health", 0).asInt();
+	m_Health              = root.get("health",         0).asInt();
 	m_AirLevel            = root.get("air",            MAX_AIR_LEVEL).asInt();
 	m_FoodLevel           = root.get("food",           MAX_FOOD_LEVEL).asInt();
 	m_FoodSaturationLevel = root.get("foodSaturation", MAX_FOOD_LEVEL).asDouble();
@@ -1743,8 +1784,8 @@ bool cPlayer::LoadFromDisk()
 	cStatSerializer StatSerializer(cRoot::Get()->GetDefaultWorld()->GetName(), GetName(), &m_Stats);
 	StatSerializer.Load();
 	
-	LOGD("Player \"%s\" was read from file, spawning at {%.2f, %.2f, %.2f} in world \"%s\"",
-		GetName().c_str(), GetPosX(), GetPosY(), GetPosZ(), m_LoadedWorldName.c_str()
+	LOGD("Player \"%s\" was read from file \"%s\", spawning at {%.2f, %.2f, %.2f} in world \"%s\"",
+		GetName().c_str(), a_FileName.c_str(), GetPosX(), GetPosY(), GetPosZ(), m_LoadedWorldName.c_str()
 	);
 	
 	return true;
@@ -1757,6 +1798,7 @@ bool cPlayer::LoadFromDisk()
 bool cPlayer::SaveToDisk()
 {
 	cFile::CreateFolder(FILE_IO_PREFIX + AString("players"));
+	cFile::CreateFolder(FILE_IO_PREFIX + AString("players/") + m_UUID.substr(0, 2));
 
 	// create the JSON data
 	Json::Value JSON_PlayerPosition;
@@ -1788,33 +1830,45 @@ bool cPlayer::SaveToDisk()
 	root["foodSaturation"]      = m_FoodSaturationLevel;
 	root["foodTickTimer"]       = m_FoodTickTimer;
 	root["foodExhaustion"]      = m_FoodExhaustionLevel;
-	root["world"]               = GetWorld()->GetName();
 	root["isflying"]            = IsFlying();
-
-	if (m_GameMode == GetWorld()->GetGameMode())
+	root["lastknownname"]       = GetName();
+	if (m_World != NULL)
 	{
-		root["gamemode"] = (int) eGameMode_NotSet;
+		root["world"] = m_World->GetName();
+		if (m_GameMode == m_World->GetGameMode())
+		{
+			root["gamemode"] = (int) eGameMode_NotSet;
+		}
+		else
+		{
+			root["gamemode"] = (int) m_GameMode;
+		}
 	}
 	else
 	{
-		root["gamemode"] = (int) m_GameMode;
+		// This happens if the player is saved to new format after loading from the old format
+		root["world"]    = m_LoadedWorldName;
+		root["gamemode"] = (int) eGameMode_NotSet;
 	}
 
 	Json::StyledWriter writer;
 	std::string JsonData = writer.write(root);
 
-	AString SourceFile;
-	Printf(SourceFile, "players/%s.json", GetName().c_str() );
+	AString SourceFile = GetUUIDFileName(m_UUID);
 
 	cFile f;
 	if (!f.Open(SourceFile, cFile::fmWrite))
 	{
-		LOGERROR("ERROR WRITING PLAYER \"%s\" TO FILE \"%s\" - cannot open file", GetName().c_str(), SourceFile.c_str());
+		LOGWARNING("Error writing player \"%s\" to file \"%s\" - cannot open file. Player will lose their progress.",
+			GetName().c_str(), SourceFile.c_str()
+		);
 		return false;
 	}
 	if (f.Write(JsonData.c_str(), JsonData.size()) != (int)JsonData.size())
 	{
-		LOGERROR("ERROR WRITING PLAYER JSON TO FILE \"%s\"", SourceFile.c_str()); 
+		LOGWARNING("Error writing player \"%s\" to file \"%s\" - cannot save data. Player will lose their progress. ",
+			GetName().c_str(), SourceFile.c_str()
+		); 
 		return false;
 	}
 
@@ -1823,7 +1877,7 @@ bool cPlayer::SaveToDisk()
 	cStatSerializer StatSerializer(cRoot::Get()->GetDefaultWorld()->GetName(), GetName(), &m_Stats);
 	if (!StatSerializer.Save())
 	{
-		LOGERROR("Could not save stats for player %s", GetName().c_str());
+		LOGWARNING("Could not save stats for player %s", GetName().c_str());
 		return false;
 	}
 
@@ -2125,3 +2179,19 @@ void cPlayer::Detach()
 
 
 
+
+AString cPlayer::GetUUIDFileName(const AString & a_UUID)
+{
+	ASSERT(a_UUID.size() == 36);
+	
+	AString res("players/");
+	res.append(a_UUID, 0, 2);
+	res.push_back('/');
+	res.append(a_UUID, 2, AString::npos);
+	res.append(".json");
+	return res;
+}
+
+
+
+
diff --git a/src/Entities/Player.h b/src/Entities/Player.h
index 2053305ea..5aebe861a 100644
--- a/src/Entities/Player.h
+++ b/src/Entities/Player.h
@@ -41,6 +41,7 @@ public:
 	
 
 	cPlayer(cClientHandle * a_Client, const AString & a_PlayerName);
+	
 	virtual ~cPlayer();
 
 	virtual void SpawnOn(cClientHandle & a_Client) override;
@@ -335,7 +336,15 @@ public:
 	bool MoveToWorld(const char * a_WorldName);  // tolua_export
 
 	bool SaveToDisk(void);
+	
+	/** Loads the player data from the disk file.
+	Returns true on success, false on failure. */
 	bool LoadFromDisk(void);
+	
+	/** Loads the player data from the specified file.
+	Returns true on success, false on failure. */
+	bool LoadFromFile(const AString & a_FileName);
+	
 	void LoadPermissionsFromDisk(void);											// tolua_export
 
 	const AString & GetLoadedWorldName() { return m_LoadedWorldName; }
@@ -514,6 +523,24 @@ protected:
 
 	cStatManager m_Stats;
 
+	/** Flag representing whether the player is currently in a bed
+	Set by a right click on unoccupied bed, unset by a time fast forward or teleport */
+	bool m_bIsInBed;
+
+	/** How long till the player's inventory will be saved
+	Default save interval is #defined in PLAYER_INVENTORY_SAVE_INTERVAL */
+	unsigned int m_TicksUntilNextSave;
+
+	/** Flag used by food handling system to determine whether a teleport has just happened
+	Will not apply food penalties if found to be true; will set to false after processing
+	*/
+	bool m_bIsTeleporting;
+	
+	/** The UUID of the player, as read from the ClientHandle.
+	If no ClientHandle is given, the UUID is initialized to empty. */
+	AString m_UUID;
+
+
 	/** Sets the speed and sends it to the client, so that they are forced to move so. */
 	virtual void DoSetSpeed(double a_SpeedX, double a_SpeedY, double a_SpeedZ) override;
 
@@ -540,19 +567,9 @@ protected:
 	/** Adds food exhaustion based on the difference between Pos and LastPos, sprinting status and swimming (in water block) */
 	void ApplyFoodExhaustionFromMovement();
 
-	/** Flag representing whether the player is currently in a bed
-	Set by a right click on unoccupied bed, unset by a time fast forward or teleport */
-	bool m_bIsInBed;
-
-	/** How long till the player's inventory will be saved
-	Default save interval is #defined in PLAYER_INVENTORY_SAVE_INTERVAL */
-	unsigned int m_TicksUntilNextSave;
-
-	/** Flag used by food handling system to determine whether a teleport has just happened
-	Will not apply food penalties if found to be true; will set to false after processing
-	*/
-	bool m_bIsTeleporting;
-
+	/** Returns the filename for the player data based on the UUID given.
+	This can be used both for online and offline UUIDs. */
+	AString GetUUIDFileName(const AString & a_UUID);
 } ; // tolua_export
 
 
diff --git a/src/Generating/Prefabs/PlainsVillagePrefabs.cpp b/src/Generating/Prefabs/PlainsVillagePrefabs.cpp
index bba493bf1..bad8dae74 100644
--- a/src/Generating/Prefabs/PlainsVillagePrefabs.cpp
+++ b/src/Generating/Prefabs/PlainsVillagePrefabs.cpp
@@ -356,7 +356,8 @@ const cPrefab::sDef g_PlainsVillagePrefabs[] =
 		"e:  8: 0\n"  /* water */
 		"f: 50: 5\n"  /* torch */
 		"g: 59: 7\n"  /* crops */
-		"h:111: 0\n"  /* lilypad */
+		"h: 59: 0\n"  /* crops */
+		"i: 59: 1\n"  /* crops */
 		"m: 19: 0\n"  /* sponge */,
 
 		// Block data:
@@ -404,12 +405,12 @@ const cPrefab::sDef g_PlainsVillagePrefabs[] =
 		/*    *   012345678901234 */
 		/*  0 */ "f.....f.f.....f"
 		/*  1 */ ".gg.gg...gg.gg."
-		/*  2 */ ".g...g...gg.gg."
-		/*  3 */ ".g.......gg.gg."
-		/*  4 */ ".gg..g...gg.gg."
-		/*  5 */ ".gg..g...gg.gg."
-		/*  6 */ "..g..g...gghgg."
-		/*  7 */ "..g.g....gg.gg."
+		/*  2 */ ".gh.hg...gg.gg."
+		/*  3 */ ".gh.ih...gg.gg."
+		/*  4 */ ".gg.hg...gg.gg."
+		/*  5 */ ".gg.hg...gg.gg."
+		/*  6 */ ".ig.hg...gg.gg."
+		/*  7 */ ".hg.gh...gg.gg."
 		/*  8 */ "f.....f.f.....f"
 
 		// Level 4
diff --git a/src/Server.cpp b/src/Server.cpp
index 2c695cc70..5d1e51036 100644
--- a/src/Server.cpp
+++ b/src/Server.cpp
@@ -258,6 +258,9 @@ bool cServer::InitServer(cIniFile & a_SettingsIni)
 		m_ServerID.resize(16, '0');
 	}
 	
+	m_ShouldLoadOfflinePlayerData = a_SettingsIni.GetValueSetB("PlayerData", "LoadOfflinePlayerData", false);
+	m_ShouldLoadNamedPlayerData   = a_SettingsIni.GetValueSetB("PlayerData", "LoadNamedPlayerData", true);
+	
 	m_ClientViewDistance = a_SettingsIni.GetValueSetI("Server", "DefaultViewDistance", cClientHandle::DEFAULT_VIEW_DISTANCE);
 	if (m_ClientViewDistance < cClientHandle::MIN_VIEW_DISTANCE)
 	{
diff --git a/src/Server.h b/src/Server.h
index 3d76c8ccf..5227799e8 100644
--- a/src/Server.h
+++ b/src/Server.h
@@ -112,8 +112,18 @@ public:												// tolua_export
 	cRsaPrivateKey & GetPrivateKey(void) { return m_PrivateKey; }
 	const AString & GetPublicKeyDER(void) const { return m_PublicKeyDER; }
 	
+	/** Returns true if authentication has been turned on in server settings. */
 	bool ShouldAuthenticate(void) const { return m_ShouldAuthenticate; }
 	
+	/** Returns true if offline UUIDs should be used to load data for players whose normal UUIDs cannot be found.
+	Loaded from the settings.ini [PlayerData].LoadOfflinePlayerData setting. */
+	bool ShouldLoadOfflinePlayerData(void) const { return m_ShouldLoadOfflinePlayerData; }
+	
+	/** Returns true if old-style playernames should be used to load data for players whose regular datafiles cannot be found.
+	This allows a seamless transition from name-based to UUID-based player storage.
+	Loaded from the settings.ini [PlayerData].LoadNamedPlayerData setting. */
+	bool ShouldLoadNamedPlayerData(void) const { return m_ShouldLoadNamedPlayerData; }
+	
 private:
 
 	friend class cRoot; // so cRoot can create and destroy cServer
@@ -204,6 +214,16 @@ private:
 	This setting is the same as the "online-mode" setting in Vanilla. */
 	bool m_ShouldAuthenticate;
 	
+	/** True if offline UUIDs should be used to load data for players whose normal UUIDs cannot be found.
+	This allows transitions from an offline (no-auth) server to an online one.
+	Loaded from the settings.ini [PlayerData].LoadOfflinePlayerData setting. */
+	bool m_ShouldLoadOfflinePlayerData;
+	
+	/** True if old-style playernames should be used to load data for players whose regular datafiles cannot be found.
+	This allows a seamless transition from name-based to UUID-based player storage.
+	Loaded from the settings.ini [PlayerData].LoadNamedPlayerData setting. */
+	bool m_ShouldLoadNamedPlayerData;
+
 
 	cServer(void);
 
diff --git a/src/Vector3.h b/src/Vector3.h
index 9e855b8af..c175bf135 100644
--- a/src/Vector3.h
+++ b/src/Vector3.h
@@ -316,6 +316,15 @@ protected:
 
 
 
+template <> inline Vector3<int> Vector3<int>::Floor(void) const
+{
+	return *this;
+}
+
+
+
+
+
 template <typename T>
 const double Vector3<T>::EPS = 0.000001;
 
diff --git a/src/World.cpp b/src/World.cpp
index a6607de12..f91a15260 100644
--- a/src/World.cpp
+++ b/src/World.cpp
@@ -3033,6 +3033,15 @@ void cWorld::TabCompleteUserName(const AString & a_Text, AStringVector & a_Resul
 
 
 
+void cWorld::SetChunkAlwaysTicked(int a_ChunkX, int a_ChunkZ, bool a_AlwaysTicked)
+{
+	m_ChunkMap->SetChunkAlwaysTicked(a_ChunkX, a_ChunkZ, a_AlwaysTicked);
+}
+
+
+
+
+
 cRedstoneSimulator * cWorld::InitializeRedstoneSimulator(cIniFile & a_IniFile)
 {
 	AString SimulatorName = a_IniFile.GetValueSet("Physics", "RedstoneSimulator", "");
diff --git a/src/World.h b/src/World.h
index 476a49739..f903ff5be 100644
--- a/src/World.h
+++ b/src/World.h
@@ -772,6 +772,13 @@ public:
 
 	/** Get the current darkness level based on the time */
 	NIBBLETYPE GetSkyDarkness() { return m_SkyDarkness; }
+	
+	/** Increments (a_AlwaysTicked == true) or decrements (false) the m_AlwaysTicked counter for the specified chunk.
+	If the m_AlwaysTicked counter is greater than zero, the chunk is ticked in the tick-thread regardless of
+	whether it has any clients or not.
+	This function allows nesting and task-concurrency (multiple separate tasks can request ticking and as long
+	as at least one requests is active the chunk will be ticked). */
+	void SetChunkAlwaysTicked(int a_ChunkX, int a_ChunkZ, bool a_AlwaysTicked = true);  // tolua_export
 
 private: