From f5a4d4f8f4674def8b151a6fc3bee8a3b46bb20c Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
Date: Sun, 5 Jan 2014 09:35:01 +1100
Subject: [PATCH] Fix Biome Decoration Crashes

We don't really know what affect this will have on the terrain generation, but its better than crashing and not having terrain generate at all!

diff --git a/src/main/java/net/minecraft/server/BiomeDecorator.java b/src/main/java/net/minecraft/server/BiomeDecorator.java
index b048d6c..962d719 100644
--- a/src/main/java/net/minecraft/server/BiomeDecorator.java
+++ b/src/main/java/net/minecraft/server/BiomeDecorator.java
@@ -147,7 +147,7 @@ public class BiomeDecorator {
         for (j = 0; j < this.z; ++j) {
             k = this.c + this.b.nextInt(16) + 8;
             l = this.d + this.b.nextInt(16) + 8;
-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2);
+            i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); // Spigot
             WorldGenerator worldgenerator = biomebase.b(this.b);
 
             worldgenerator.a(this.a, this.b, k, i1, l);
@@ -156,7 +156,7 @@ public class BiomeDecorator {
         for (j = 0; j < this.A; ++j) {
             k = this.c + this.b.nextInt(16) + 8;
             l = this.d + this.b.nextInt(16) + 8;
-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2);
+            i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); // Spigot
             (new WorldGenDeadBush(Blocks.DEAD_BUSH)).a(this.a, this.b, k, i1, l);
         }
 
@@ -164,7 +164,7 @@ public class BiomeDecorator {
             k = this.c + this.b.nextInt(16) + 8;
             l = this.d + this.b.nextInt(16) + 8;
 
-            for (i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2); i1 > 0 && this.a.isEmpty(k, i1 - 1, l); --i1) {
+            for (i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); i1 > 0 && this.a.isEmpty(k, i1 - 1, l); --i1) { // Spigot
                 ;
             }
 
@@ -182,7 +182,7 @@ public class BiomeDecorator {
             if (this.b.nextInt(8) == 0) {
                 k = this.c + this.b.nextInt(16) + 8;
                 l = this.d + this.b.nextInt(16) + 8;
-                i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2);
+                i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); // Spigot
                 this.r.a(this.a, this.b, k, i1, l);
             }
         }
@@ -190,42 +190,42 @@ public class BiomeDecorator {
         if (this.b.nextInt(4) == 0) {
             j = this.c + this.b.nextInt(16) + 8;
             k = this.d + this.b.nextInt(16) + 8;
-            l = this.b.nextInt(this.a.getHighestBlockYAt(j, k) * 2);
+            l = this.b.nextInt(this.getHighestBlockYAt(j, k) * 2); // Spigot
             this.q.a(this.a, this.b, j, l, k);
         }
 
         if (this.b.nextInt(8) == 0) {
             j = this.c + this.b.nextInt(16) + 8;
             k = this.d + this.b.nextInt(16) + 8;
-            l = this.b.nextInt(this.a.getHighestBlockYAt(j, k) * 2);
+            l = this.b.nextInt(this.getHighestBlockYAt(j, k) * 2); // Spigot
             this.r.a(this.a, this.b, j, l, k);
         }
 
         for (j = 0; j < this.C; ++j) {
             k = this.c + this.b.nextInt(16) + 8;
             l = this.d + this.b.nextInt(16) + 8;
-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2);
+            i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); // Spigot
             this.t.a(this.a, this.b, k, i1, l);
         }
 
         for (j = 0; j < 10; ++j) {
             k = this.c + this.b.nextInt(16) + 8;
             l = this.d + this.b.nextInt(16) + 8;
-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2);
+            i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); // Spigot
             this.t.a(this.a, this.b, k, i1, l);
         }
 
         if (this.b.nextInt(32) == 0) {
             j = this.c + this.b.nextInt(16) + 8;
             k = this.d + this.b.nextInt(16) + 8;
-            l = this.b.nextInt(this.a.getHighestBlockYAt(j, k) * 2);
+            l = this.b.nextInt(this.getHighestBlockYAt(j, k) * 2); // Spigot
             (new WorldGenPumpkin()).a(this.a, this.b, j, l, k);
         }
 
         for (j = 0; j < this.D; ++j) {
             k = this.c + this.b.nextInt(16) + 8;
             l = this.d + this.b.nextInt(16) + 8;
-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(k, l) * 2);
+            i1 = this.b.nextInt(this.getHighestBlockYAt(k, l) * 2); // Spigot
             this.u.a(this.a, this.b, k, i1, l);
         }
 
@@ -276,4 +276,11 @@ public class BiomeDecorator {
         this.a(1, this.n, 0, 16);
         this.b(1, this.o, 16, 16);
     }
+
+    // Spigot Start
+    private int getHighestBlockYAt(int x, int z)
+    {
+        return Math.max( 1, this.a.getHighestBlockYAt( x, z ) );
+    }
+    // Spigot End
 }
-- 
1.8.3.2