Default to Y=1 when a Y=0 BlockPosition is found to be used in the BiomeDecorator. This prevents the "n must be positive" Crash due to the fact that sometimes the heightMap can be wrong calculated. Fixes SPIGOT-91

1 files changed, 139 insertions, 0 deletions

diff --git a/nms-patches/BiomeDecorator.patch b/nms-patches/BiomeDecorator.patch
new file mode 100644
index 00000000..91b04ca2
--- /dev/null
+++ b/nms-patches/BiomeDecorator.patch
@@ -0,0 +1,139 @@
+--- ../work/decompile-8eb82bde//net/minecraft/server/BiomeDecorator.java	Tue Dec  2 23:22:43 2014
++++ src/main/java/net/minecraft/server/BiomeDecorator.java	Tue Dec  2 23:22:34 2014
+@@ -132,7 +132,7 @@
+             WorldGenTreeAbstract worldgentreeabstract = biomebase.a(this.b);
+ 
+             worldgentreeabstract.e();
+-            blockposition = this.a.getHighestBlockYAt(this.c.a(k, 0, l));
++            blockposition = this.getHighestBlockYAt(this.c.a(k, 0, l)); // CraftBukkit - Prevent crash
+             if (worldgentreeabstract.generate(this.a, this.b, blockposition)) {
+                 worldgentreeabstract.a(this.a, this.b, blockposition);
+             }
+@@ -141,7 +141,7 @@
+         for (j = 0; j < this.K; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            this.v.generate(this.a, this.b, this.a.getHighestBlockYAt(this.c.a(k, 0, l)));
++            this.v.generate(this.a, this.b, this.getHighestBlockYAt(this.c.a(k, 0, l ))); // CraftBukkit - Prevent crash
+         }
+ 
+         int i1;
+@@ -149,7 +149,7 @@
+         for (j = 0; j < this.B; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() + 32);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() + 32); // CraftBukkit - Prevent crash
+             blockposition = this.c.a(k, i1, l);
+             EnumFlowerVarient enumflowervarient = biomebase.a(this.b, blockposition);
+             BlockFlowers blockflowers = enumflowervarient.a().a();
+@@ -163,14 +163,14 @@
+         for (j = 0; j < this.C; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+             biomebase.b(this.b).generate(this.a, this.b, this.c.a(k, i1, l));
+         }
+ 
+         for (j = 0; j < this.D; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+             (new WorldGenDeadBush()).generate(this.a, this.b, this.c.a(k, i1, l));
+         }
+ 
+@@ -179,7 +179,7 @@
+         while (j < this.z) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+             blockposition = this.c.a(k, i1, l);
+ 
+             while (true) {
+@@ -202,7 +202,7 @@
+             if (this.b.nextInt(4) == 0) {
+                 k = this.b.nextInt(16) + 8;
+                 l = this.b.nextInt(16) + 8;
+-                BlockPosition blockposition2 = this.a.getHighestBlockYAt(this.c.a(k, 0, l));
++                BlockPosition blockposition2 = this.getHighestBlockYAt(this.c.a(k, 0, l)); // CraftBukkit - Prevent crash
+ 
+                 this.t.generate(this.a, this.b, blockposition2);
+             }
+@@ -210,7 +210,7 @@
+             if (this.b.nextInt(8) == 0) {
+                 k = this.b.nextInt(16) + 8;
+                 l = this.b.nextInt(16) + 8;
+-                i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++                i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+                 blockposition = this.c.a(k, i1, l);
+                 this.u.generate(this.a, this.b, blockposition);
+             }
+@@ -219,42 +219,42 @@
+         if (this.b.nextInt(4) == 0) {
+             j = this.b.nextInt(16) + 8;
+             k = this.b.nextInt(16) + 8;
+-            l = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(j, 0, k)).getY() * 2);
++            l = this.b.nextInt(this.getHighestBlockYAt(this.c.a(j, 0, k)).getY() * 2); // CraftBukkit - Prevent crash
+             this.t.generate(this.a, this.b, this.c.a(j, l, k));
+         }
+ 
+         if (this.b.nextInt(8) == 0) {
+             j = this.b.nextInt(16) + 8;
+             k = this.b.nextInt(16) + 8;
+-            l = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(j, 0, k)).getY() * 2);
++            l = this.b.nextInt(this.getHighestBlockYAt(this.c.a(j, 0, k)).getY() * 2); // CraftBukkit - Prevent crash
+             this.u.generate(this.a, this.b, this.c.a(j, l, k));
+         }
+ 
+         for (j = 0; j < this.F; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+             this.w.generate(this.a, this.b, this.c.a(k, i1, l));
+         }
+ 
+         for (j = 0; j < 10; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+             this.w.generate(this.a, this.b, this.c.a(k, i1, l));
+         }
+ 
+         if (this.b.nextInt(32) == 0) {
+             j = this.b.nextInt(16) + 8;
+             k = this.b.nextInt(16) + 8;
+-            l = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(j, 0, k)).getY() * 2);
++            l = this.b.nextInt(this.getHighestBlockYAt(this.c.a(j, 0, k)).getY() * 2); // CraftBukkit - Prevent crash
+             (new WorldGenPumpkin()).generate(this.a, this.b, this.c.a(j, l, k));
+         }
+ 
+         for (j = 0; j < this.G; ++j) {
+             k = this.b.nextInt(16) + 8;
+             l = this.b.nextInt(16) + 8;
+-            i1 = this.b.nextInt(this.a.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2);
++            i1 = this.b.nextInt(this.getHighestBlockYAt(this.c.a(k, 0, l)).getY() * 2); // CraftBukkit - Prevent crash
+             this.x.generate(this.a, this.b, this.c.a(k, i1, l));
+         }
+ 
+@@ -273,6 +273,16 @@
+         }
+ 
+     }
++
++    // CraftBukkit start - The heightMap can be wrong calculated and return Y = 0 which will crash the Server
++    private BlockPosition getHighestBlockYAt( BlockPosition blockPosition ) {
++        BlockPosition returnBlockPosition = this.a.getHighestBlockYAt( blockPosition );
++        if ( returnBlockPosition.getY() == 0 ) {
++            returnBlockPosition = returnBlockPosition.up( 1 );
++        }
++        return returnBlockPosition;
++    }
++    // CraftBukkit end
+ 
+     protected void a(int i, WorldGenerator worldgenerator, int j, int k) {
+         int l;