From b3bc94b822f4e83bd64473abb7e6bdd585e00da7 Mon Sep 17 00:00:00 2001
From: Thinkofdeath <thethinkofdeath@gmail.com>
Date: Wed, 15 Jan 2014 21:52:47 +0000
Subject: [PATCH] Block data values that crash the client


diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 3712009..90f32ed 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -115,7 +115,7 @@ public class Chunk {
                         }
 
                         this.sections[l1].setTypeId(l, j1 & 15, i1, block);
-                        this.sections[l1].setData(l, j1 & 15, i1, abyte[k1]);
+                        this.sections[l1].setData(l, j1 & 15, i1, checkData( block, abyte[k1] ) );
                     }
                 }
             }
@@ -398,6 +398,17 @@ public class Chunk {
         }
     }
 
+    // Spigot start - prevent invalid data values
+    private static int checkData( Block block, int l )
+    {
+        if (block == Block.b( "minecraft:double_plant" ) )
+        {
+            return l == 7 ? 0 : l;
+        }
+        return l;
+    }
+    // Spigot end
+
     public boolean a(int i, int j, int k, Block block, int l) {
         int i1 = k << 4 | i;
 
@@ -452,7 +463,7 @@ public class Chunk {
             if (chunksection.getTypeId(i, j & 15, k) != block) {
                 return false;
             } else {
-                chunksection.setData(i, j & 15, k, l);
+                chunksection.setData(i, j & 15, k, checkData( block, l ) );
                 if (flag) {
                     this.initLighting();
                 } else {
@@ -522,8 +533,9 @@ public class Chunk {
                 return false;
             } else {
                 this.n = true;
-                chunksection.setData(i, j & 15, k, l);
-                if (chunksection.getTypeId(i, j & 15, k) instanceof IContainer) {
+                Block block = chunksection.getTypeId( i, j & 15, k );
+                chunksection.setData(i, j & 15, k, checkData( block, l ) );
+                if (block instanceof IContainer) {
                     TileEntity tileentity = this.e(i, j, k);
 
                     if (tileentity != null) {
-- 
1.8.3.2