From d2f92d223a1713c1d8fe0c45ffb28e30481209b8 Mon Sep 17 00:00:00 2001
From: tr7zw <tr7zw@live.de>
Date: Mon, 6 Apr 2020 01:05:08 +0200
Subject: [PATCH] Stop a pathfinder method to call itself more than once

This miiiight help to fix the pathfinder from going nuts. Only time will tell.
---
 .../minecraft/server/PathfinderNormal.java    | 24 +++++++++++--------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/main/java/net/minecraft/server/PathfinderNormal.java b/src/main/java/net/minecraft/server/PathfinderNormal.java
index 61e4dbcd4..f406abd84 100644
--- a/src/main/java/net/minecraft/server/PathfinderNormal.java
+++ b/src/main/java/net/minecraft/server/PathfinderNormal.java
@@ -96,49 +96,49 @@ public class PathfinderNormal extends PathfinderAbstract {
         }
 
         double d0 = a((IBlockAccess) this.a, new BlockPosition(pathpoint.a, pathpoint.b, pathpoint.c));
-        PathPoint pathpoint1 = this.a(pathpoint.a, pathpoint.b, pathpoint.c + 1, j, d0, EnumDirection.SOUTH);
+        PathPoint pathpoint1 = this.a(pathpoint.a, pathpoint.b, pathpoint.c + 1, j, d0, EnumDirection.SOUTH, 0); // YAPFA
 
         if (pathpoint1 != null && !pathpoint1.i && pathpoint1.k >= 0.0F) {
             apathpoint[i++] = pathpoint1;
         }
 
-        PathPoint pathpoint2 = this.a(pathpoint.a - 1, pathpoint.b, pathpoint.c, j, d0, EnumDirection.WEST);
+        PathPoint pathpoint2 = this.a(pathpoint.a - 1, pathpoint.b, pathpoint.c, j, d0, EnumDirection.WEST, 0); // YAPFA
 
         if (pathpoint2 != null && !pathpoint2.i && pathpoint2.k >= 0.0F) {
             apathpoint[i++] = pathpoint2;
         }
 
-        PathPoint pathpoint3 = this.a(pathpoint.a + 1, pathpoint.b, pathpoint.c, j, d0, EnumDirection.EAST);
+        PathPoint pathpoint3 = this.a(pathpoint.a + 1, pathpoint.b, pathpoint.c, j, d0, EnumDirection.EAST, 0); // YAPFA
 
         if (pathpoint3 != null && !pathpoint3.i && pathpoint3.k >= 0.0F) {
             apathpoint[i++] = pathpoint3;
         }
 
-        PathPoint pathpoint4 = this.a(pathpoint.a, pathpoint.b, pathpoint.c - 1, j, d0, EnumDirection.NORTH);
+        PathPoint pathpoint4 = this.a(pathpoint.a, pathpoint.b, pathpoint.c - 1, j, d0, EnumDirection.NORTH, 0); // YAPFA
 
         if (pathpoint4 != null && !pathpoint4.i && pathpoint4.k >= 0.0F) {
             apathpoint[i++] = pathpoint4;
         }
 
-        PathPoint pathpoint5 = this.a(pathpoint.a - 1, pathpoint.b, pathpoint.c - 1, j, d0, EnumDirection.NORTH);
+        PathPoint pathpoint5 = this.a(pathpoint.a - 1, pathpoint.b, pathpoint.c - 1, j, d0, EnumDirection.NORTH, 0); // YAPFA
 
         if (this.a(pathpoint, pathpoint2, pathpoint4, pathpoint5)) {
             apathpoint[i++] = pathpoint5;
         }
 
-        PathPoint pathpoint6 = this.a(pathpoint.a + 1, pathpoint.b, pathpoint.c - 1, j, d0, EnumDirection.NORTH);
+        PathPoint pathpoint6 = this.a(pathpoint.a + 1, pathpoint.b, pathpoint.c - 1, j, d0, EnumDirection.NORTH, 0); // YAPFA
 
         if (this.a(pathpoint, pathpoint3, pathpoint4, pathpoint6)) {
             apathpoint[i++] = pathpoint6;
         }
 
-        PathPoint pathpoint7 = this.a(pathpoint.a - 1, pathpoint.b, pathpoint.c + 1, j, d0, EnumDirection.SOUTH);
+        PathPoint pathpoint7 = this.a(pathpoint.a - 1, pathpoint.b, pathpoint.c + 1, j, d0, EnumDirection.SOUTH, 0); // YAPFA
 
         if (this.a(pathpoint, pathpoint2, pathpoint1, pathpoint7)) {
             apathpoint[i++] = pathpoint7;
         }
 
-        PathPoint pathpoint8 = this.a(pathpoint.a + 1, pathpoint.b, pathpoint.c + 1, j, d0, EnumDirection.SOUTH);
+        PathPoint pathpoint8 = this.a(pathpoint.a + 1, pathpoint.b, pathpoint.c + 1, j, d0, EnumDirection.SOUTH, 0); // YAPFA
 
         if (this.a(pathpoint, pathpoint3, pathpoint1, pathpoint8)) {
             apathpoint[i++] = pathpoint8;
@@ -159,7 +159,11 @@ public class PathfinderNormal extends PathfinderAbstract {
     }
 
     @Nullable
-    private PathPoint a(int i, int j, int k, int l, double d0, EnumDirection enumdirection) {
+    private PathPoint a(int i, int j, int k, int l, double d0, EnumDirection enumdirection, int tries) { // YAPFA
+    	if(tries > 1) {
+    		System.out.println("Stopped an entity falling into a Pathfinder loop. This might or might not be right! " + super.b.toString());
+    		return null; // YAPFA - This might stop the Pathfinder from going nuts
+    	}
         PathPoint pathpoint = null;
         BlockPosition blockposition = new BlockPosition(i, j, k);
         double d1 = a((IBlockAccess) this.a, blockposition);
@@ -181,7 +185,7 @@ public class PathfinderNormal extends PathfinderAbstract {
                 return pathpoint;
             } else {
                 if ((pathpoint == null || pathpoint.k < 0.0F) && l > 0 && pathtype != PathType.FENCE && pathtype != PathType.TRAPDOOR) {
-                    pathpoint = this.a(i, j + 1, k, l - 1, d0, enumdirection);
+                    pathpoint = this.a(i, j + 1, k, l - 1, d0, enumdirection, ++tries);
                     if (pathpoint != null && (pathpoint.l == PathType.OPEN || pathpoint.l == PathType.WALKABLE) && this.b.getWidth() < 1.0F) {
                         double d3 = (double) (i - enumdirection.getAdjacentX()) + 0.5D;
                         double d4 = (double) (k - enumdirection.getAdjacentZ()) + 0.5D;
-- 
2.25.1.windows.1