12 files changed, 371 insertions, 161 deletions

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: