From 26f5c3588e01d9aefbb838fc19d45e54ad8b096d 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/world/level/World.java b/src/main/java/net/minecraft/world/level/World.java
index 60e47cf63..57f63aa83 100644
--- a/src/main/java/net/minecraft/world/level/World.java
+++ b/src/main/java/net/minecraft/world/level/World.java
@@ -151,6 +151,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
     public final org.spigotmc.SpigotWorldConfig spigotConfig; // Spigot
 
     public final SpigotTimings.WorldTimingsHandler timings; // Spigot
+    public static BlockPosition lastPhysicsProblem; // Spigot
 
     public CraftWorld getWorld() {
         return this.world;
@@ -377,7 +378,13 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
                 // 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, j);
+                    // Spigot start
+                    try {
+                        notifyAndUpdatePhysics(blockposition, chunk, iblockdata1, iblockdata, iblockdata2, i, j);
+                    } catch (StackOverflowError ex) {
+                        lastPhysicsProblem = new BlockPosition(blockposition);
+                    }
+                    // Spigot end
                 }
                 // CraftBukkit end
 
diff --git a/src/main/java/net/minecraft/world/level/redstone/NeighborUpdater.java b/src/main/java/net/minecraft/world/level/redstone/NeighborUpdater.java
index 934fa443c..ca37ef601 100644
--- a/src/main/java/net/minecraft/world/level/redstone/NeighborUpdater.java
+++ b/src/main/java/net/minecraft/world/level/redstone/NeighborUpdater.java
@@ -64,6 +64,10 @@ public interface NeighborUpdater {
             }
             // CraftBukkit end
             iblockdata.neighborChanged(world, blockposition, block, blockposition1, flag);
+            // Spigot Start
+        } catch (StackOverflowError ex) {
+            world.lastPhysicsProblem = new BlockPosition(blockposition);
+            // Spigot End
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.forThrowable(throwable, "Exception while updating neighbours");
             CrashReportSystemDetails crashreportsystemdetails = crashreport.addCategory("Block being updated");
diff --git a/src/main/java/org/spigotmc/WatchdogThread.java b/src/main/java/org/spigotmc/WatchdogThread.java
index 4734d4ae8..b4eeeb0d0 100644
--- a/src/main/java/org/spigotmc/WatchdogThread.java
+++ b/src/main/java/org/spigotmc/WatchdogThread.java
@@ -74,6 +74,13 @@ 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.world.level.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.world.level.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().serverThread.getId(), Integer.MAX_VALUE ), log );
-- 
2.34.1