Fixed crash caused by Jukeboxes under certain circumstances.

src/main/java/net/minecraft/server/BlockJukeBox.java

@@ -0,0 +1,70 @@
+package net.minecraft.server;
+
+public class BlockJukeBox extends BlockContainer {
+
+    protected BlockJukeBox(int i, int j) {
+        super(i, j, Material.WOOD);
+    }
+
+    public int a(int i) {
+        return this.textureId + (i == 1 ? 1 : 0);
+    }
+
+    public boolean interact(World world, int i, int j, int k, EntityHuman entityhuman) {
+        if (world.getData(i, j, k) == 0) {
+            return false;
+        } else {
+            this.b_(world, i, j, k);
+            return true;
+        }
+    }
+
+    public void f(World world, int i, int j, int k, int l) {
+        if (!world.isStatic) {
+            TileEntityRecordPlayer tileentityrecordplayer = (TileEntityRecordPlayer) world.getTileEntity(i, j, k);
+
+            tileentityrecordplayer.a = l;
+            tileentityrecordplayer.update();
+            world.setData(i, j, k, 1);
+        }
+    }
+
+    public void b_(World world, int i, int j, int k) {
+        if (!world.isStatic) {
+            TileEntityRecordPlayer tileentityrecordplayer = (TileEntityRecordPlayer) world.getTileEntity(i, j, k);
+            if (tileentityrecordplayer == null) return; // CraftBukkit
+            int l = tileentityrecordplayer.a;
+
+            if (l != 0) {
+                world.e(1005, i, j, k, 0);
+                world.a((String) null, i, j, k);
+                tileentityrecordplayer.a = 0;
+                tileentityrecordplayer.update();
+                world.setData(i, j, k, 0);
+                float f = 0.7F;
+                double d0 = (double) (world.random.nextFloat() * f) + (double) (1.0F - f) * 0.5D;
+                double d1 = (double) (world.random.nextFloat() * f) + (double) (1.0F - f) * 0.2D + 0.6D;
+                double d2 = (double) (world.random.nextFloat() * f) + (double) (1.0F - f) * 0.5D;
+                EntityItem entityitem = new EntityItem(world, (double) i + d0, (double) j + d1, (double) k + d2, new ItemStack(l, 1, 0));
+
+                entityitem.pickupDelay = 10;
+                world.addEntity(entityitem);
+            }
+        }
+    }
+
+    public void remove(World world, int i, int j, int k) {
+        this.b_(world, i, j, k);
+        super.remove(world, i, j, k);
+    }
+
+    public void dropNaturally(World world, int i, int j, int k, int l, float f) {
+        if (!world.isStatic) {
+            super.dropNaturally(world, i, j, k, l, f);
+        }
+    }
+
+    protected TileEntity a_() {
+        return new TileEntityRecordPlayer();
+    }
+}