From 9b147af30cb550f5e5a8c27696a048041c6e7368 Mon Sep 17 00:00:00 2001
From: David <dmck2b@gmail.com>
Date: Mon, 21 Apr 2014 12:43:08 +0100
Subject: [PATCH] Prevent NoClassDefError crash and notify on crash


diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index d3e8fdae2..02ddf3938 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -132,6 +132,7 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
 
     public final SpigotTimings.WorldTimingsHandler timings; // Spigot
     private boolean guardEntityList; // Spigot
+    public static BlockPosition lastPhysicsProblem; // Spigot
 
     public CraftWorld getWorld() {
         return this.world;
@@ -352,7 +353,13 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
                 // CraftBukkit start
                 if (!this.captureBlockStates) { // Don't notify clients or update physics while capturing blockstates
                     // Modularize client and physic updates
-                    notifyAndUpdatePhysics(blockposition, chunk, iblockdata1, iblockdata, iblockdata2, i);
+                    // Spigot start
+                    try {
+                        notifyAndUpdatePhysics(blockposition, chunk, iblockdata1, iblockdata, iblockdata2, i);
+                    } catch (StackOverflowError ex) {
+                        lastPhysicsProblem = new BlockPosition(blockposition);
+                    }
+                    // Spigot end
                 }
                 // CraftBukkit end
 
@@ -532,6 +539,10 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
                 }
                 // CraftBukkit end
                 iblockdata.doPhysics(this, blockposition, block, blockposition1);
+            // Spigot Start
+            } catch (StackOverflowError ex) { 
+                lastPhysicsProblem = new BlockPosition(blockposition);
+                // Spigot End
             } catch (Throwable throwable) {
                 CrashReport crashreport = CrashReport.a(throwable, "Exception while updating neighbours");
                 CrashReportSystemDetails crashreportsystemdetails = crashreport.a("Block being updated");
diff --git a/src/main/java/org/spigotmc/WatchdogThread.java b/src/main/java/org/spigotmc/WatchdogThread.java
index 1d60ddf0d..9511f247a 100644
--- a/src/main/java/org/spigotmc/WatchdogThread.java
+++ b/src/main/java/org/spigotmc/WatchdogThread.java
@@ -70,6 +70,13 @@ public class WatchdogThread extends Thread
                 log.log( Level.SEVERE, "Be sure to include ALL relevant console errors and Minecraft crash reports" );
                 log.log( Level.SEVERE, "Spigot version: " + Bukkit.getServer().getVersion() );
                 //
+                if ( net.minecraft.server.World.lastPhysicsProblem != null )
+                {
+                    log.log( Level.SEVERE, "------------------------------" );
+                    log.log( Level.SEVERE, "During the run of the server, a physics stackoverflow was supressed" );
+                    log.log( Level.SEVERE, "near " + net.minecraft.server.World.lastPhysicsProblem );
+                }
+                //
                 log.log( Level.SEVERE, "------------------------------" );
                 log.log( Level.SEVERE, "Server thread dump (Look for plugins here before reporting to Spigot!):" );
                 dumpThread( ManagementFactory.getThreadMXBean().getThreadInfo( MinecraftServer.getServer().primaryThread.getId(), Integer.MAX_VALUE ), log );
-- 
2.19.1