Paper/nms-patches/WorldBorder.patch

--- a/net/minecraft/server/WorldBorder.java
+++ b/net/minecraft/server/WorldBorder.java
@@ -18,6 +18,7 @@
     private double j;
     private int k;
     private int l;
+    public WorldServer world; // CraftBukkit
 
     public WorldBorder() {
         this.e = this.d;
@@ -32,8 +33,19 @@
         return (double) (blockposition.getX() + 1) > this.b() && (double) blockposition.getX() < this.d() && (double) (blockposition.getZ() + 1) > this.c() && (double) blockposition.getZ() < this.e();
     }
 
+    // CraftBukkit start - split method
     public boolean isInBounds(ChunkCoordIntPair chunkcoordintpair) {
-        return (double) chunkcoordintpair.e() > this.b() && (double) chunkcoordintpair.c() < this.d() && (double) chunkcoordintpair.f() > this.c() && (double) chunkcoordintpair.d() < this.e();
+        return isInBounds(chunkcoordintpair.x, chunkcoordintpair.z);
+    }
+
+    // Inlined the getters from ChunkCoordIntPair
+    public boolean isInBounds(long chunkcoords) {
+        return isInBounds(org.bukkit.craftbukkit.util.LongHash.msw(chunkcoords), org.bukkit.craftbukkit.util.LongHash.lsw(chunkcoords));
+    }
+
+    // Inlined the getters from ChunkCoordIntPair
+    public boolean isInBounds(int x, int z) {
+        return (double) ((x  << 4) + 15) > this.b() && (double) (x << 4) < this.d() && (double) ((z  << 4) + 15) > this.c() && (double) (x << 4) < this.e();
     }
 
     public boolean a(AxisAlignedBB axisalignedbb) {
@@ -177,6 +189,7 @@
     }
 
     public void a(IWorldBorderListener iworldborderlistener) {
+        if (a.contains(iworldborderlistener)) return; // CraftBukkit
         this.a.add(iworldborderlistener);
     }