Fix stale held item appearing when switching worlds (#910)

Signed-off-by: Ayush Thoren <ayushthoren@gmail.com>

Minecraft.Client/ItemInHandRenderer.cpp

@@ -930,6 +930,14 @@ void ItemInHandRenderer::tick()
 
 }
 
+void ItemInHandRenderer::reset()
+{
+	selectedItem = nullptr;
+	lastSlot = -1;
+	height = 0.0f;
+	oHeight = 0.0f;
+}
+
 void ItemInHandRenderer::itemPlaced()
 {
 	height = 0;

Minecraft.Client/ItemInHandRenderer.h

@@ -41,6 +41,7 @@ private:
     int lastSlot;
 public:
 	void tick();
+	void reset();
     void itemPlaced();
     void itemUsed();
 };

Minecraft.Client/Minecraft.cpp

@@ -10,6 +10,7 @@
 #include "User.h"
 #include "Textures.h"
 #include "GameRenderer.h"
+#include "ItemInHandRenderer.h"
 #include "HumanoidModel.h"
 #include "Options.h"
 #include "TexturePackRepository.h"
@@ -217,6 +218,7 @@ Minecraft::Minecraft(Component *mouseComponent, Canvas *parent, MinecraftApplet
 		m_pendingLocalConnections[i] = NULL;
 		m_connectionFailed[i] = false;
 		localgameModes[i]=NULL;
+		localitemInHandRenderers[i] = NULL;
 	}
 
 	animateTickLevel = NULL;	// 4J added
@@ -4240,6 +4242,17 @@ void Minecraft::setLevel(MultiPlayerLevel *level, int message /*=-1*/, shared_pt
 	// 4J - stop update thread from processing this level, which blocks until it is safe to move on - will be re-enabled if we set the level to be non-NULL
 	gameRenderer->DisableUpdateThread();
 
+	if (level == NULL || player == NULL)
+	{
+		for (int i = 0; i < XUSER_MAX_COUNT; ++i)
+		{
+			if (localitemInHandRenderers[i] != NULL)
+			{
+				localitemInHandRenderers[i]->reset();
+			}
+		}
+	}
+
 	for(unsigned int i = 0; i < levels.length; ++i)
 	{
 		// 4J We only need to save out in multiplayer is we are setting the level to NULL