Better fix for #312, null checking for the chisel item in the GUI

src/main/java/com/cricketcraft/chisel/api/IMC.java

@@ -1,8 +1,9 @@
 package com.cricketcraft.chisel.api;
 
-
 /**
  * Use the enum constants (using {@link #key} or calling {@link #toString()}) in this class as keys for IMC messages sent to chisel
+ * <p>
+ * It is also acceptable to copy the Strings in this class to avoid referencing this API.
  */
 public enum IMC {
 
@@ -56,7 +57,7 @@ public enum IMC {
 	 */
 	@Deprecated
 	public static final String CHISEL_MODID = "chisel";
-	
+
 	public static final String getModid() {
 		return ChiselAPIProps.MOD_ID;
 	}

src/main/java/com/cricketcraft/chisel/inventory/ContainerChisel.java

@@ -50,7 +50,7 @@ public class ContainerChisel extends Container {
 		}
 
 		chisel = inventoryplayer.getCurrentItem();
-		if (chisel.stackTagCompound != null) {
+		if (chisel != null && chisel.stackTagCompound != null) {
 			ItemStack stack = ItemStack.loadItemStackFromNBT(chisel.stackTagCompound.getCompoundTag("chiselTarget"));
 			inventory.setInventorySlotContents(InventoryChiselSelection.normalSlots, stack);
 		}

src/main/java/com/cricketcraft/chisel/item/chisel/ChiselController.java

@@ -105,7 +105,7 @@ public final class ChiselController {
 			} else {
 				lastTickClick = event.world.getTotalWorldTime();
 			}
-			if (!event.world.isRemote && chisel.canOpenGui(event.world, event.entityPlayer, held) && event.world.getTileEntity(event.x, event.y, event.z) == null) {
+			if (!event.world.isRemote && chisel.canOpenGui(event.world, event.entityPlayer, held)) {
 				event.entityPlayer.openGui(Chisel.instance, 0, event.world, 0, 0, 0);
 			}
 			break;

src/main/java/com/cricketcraft/chisel/network/ChiselGuiHandler.java

@@ -22,8 +22,7 @@ public class ChiselGuiHandler implements IGuiHandler {
 	public Object getServerGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z) {
 		switch (ID) {
 		case 0:
-			if (player.getCurrentEquippedItem() != null)
-				return new ContainerChisel(player.inventory, new InventoryChiselSelection(player.getCurrentEquippedItem()));
+			return new ContainerChisel(player.inventory, new InventoryChiselSelection(player.getCurrentEquippedItem()));
 		case 1:
 			TileEntity tileentity = world.getTileEntity(x, y, z);
 			if (tileentity instanceof TileEntityAutoChisel)
@@ -41,8 +40,7 @@ public class ChiselGuiHandler implements IGuiHandler {
 	public Object getClientGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z) {
 		switch (ID) {
 		case 0:
-			if (player.getCurrentEquippedItem() != null)
-				return new GuiChisel(player.inventory, new InventoryChiselSelection(player.getCurrentEquippedItem()));
+			return new GuiChisel(player.inventory, new InventoryChiselSelection(player.getCurrentEquippedItem()));
 		case 1:
 			TileEntity tileentity = world.getTileEntity(x, y, z);
 			if (tileentity instanceof TileEntityAutoChisel)

src/main/java/com/cricketcraft/chisel/utils/General.java

@@ -126,6 +126,10 @@ public class General {
 
 	private static final String MODE_KEY = "chiselMode";
 	public static IChiselMode getChiselMode(ItemStack chisel) {
+		if (chisel == null) {
+			return ChiselMode.SINGLE;
+		}
+		
 		if (chisel.stackTagCompound == null || Strings.isNullOrEmpty(chisel.stackTagCompound.getString(MODE_KEY))) {
 			initTag(chisel);
 			chisel.stackTagCompound.setString(MODE_KEY, ChiselMode.SINGLE.name());