PaperMC/nms-patches/EntityHanging.patch

--- a/net/minecraft/server/EntityHanging.java
+++ b/net/minecraft/server/EntityHanging.java
@@ -4,10 +4,17 @@
 import java.util.List;
 import org.apache.commons.lang3.Validate;
 
+// CraftBukkit start
+import org.bukkit.entity.Hanging;
+import org.bukkit.entity.Painting;
+import org.bukkit.event.hanging.HangingBreakEvent;
+import org.bukkit.event.painting.PaintingBreakEvent;
+// CraftBukkit end
+
 public abstract class EntityHanging extends Entity {
 
     private int c;
-    protected BlockPosition blockPosition;
+    public BlockPosition blockPosition; // CraftBukkit - public
     public EnumDirection direction;
 
     public EntityHanging(World world) {
@@ -22,7 +29,7 @@
 
     protected void h() {}
 
-    protected void setDirection(EnumDirection enumdirection) {
+    public void setDirection(EnumDirection enumdirection) { // CraftBukkit - public
         Validate.notNull(enumdirection);
         Validate.isTrue(enumdirection.k().c());
         this.direction = enumdirection;
@@ -30,30 +37,34 @@
         this.updateBoundingBox();
     }
 
-    private void updateBoundingBox() {
-        if (this.direction != null) {
-            double d0 = (double) this.blockPosition.getX() + 0.5D;
-            double d1 = (double) this.blockPosition.getY() + 0.5D;
-            double d2 = (double) this.blockPosition.getZ() + 0.5D;
+    /* CraftBukkit start - bounding box calculation made static (for spawn usage)
+
+        l is from function l()
+        m is from function m()
+
+        Placing here as it's more likely to be noticed as something which needs to be updated
+        then something in a CraftBukkit file.
+     */
+    public static AxisAlignedBB calculateBoundingBox(BlockPosition blockPosition, EnumDirection direction, int width, int height) {
+            double d0 = (double) blockPosition.getX() + 0.5D;
+            double d1 = (double) blockPosition.getY() + 0.5D;
+            double d2 = (double) blockPosition.getZ() + 0.5D;
             double d3 = 0.46875D;
-            double d4 = this.a(this.l());
-            double d5 = this.a(this.m());
+            double d4 = width % 32 == 0 ? 0.5D : 0.0D;
+            double d5 = height % 32 == 0 ? 0.5D : 0.0D;
 
-            d0 -= (double) this.direction.getAdjacentX() * 0.46875D;
-            d2 -= (double) this.direction.getAdjacentZ() * 0.46875D;
+            d0 -= (double) direction.getAdjacentX() * 0.46875D;
+            d2 -= (double) direction.getAdjacentZ() * 0.46875D;
             d1 += d5;
-            EnumDirection enumdirection = this.direction.f();
+            EnumDirection enumdirection = direction.f();
 
             d0 += d4 * (double) enumdirection.getAdjacentX();
             d2 += d4 * (double) enumdirection.getAdjacentZ();
-            this.locX = d0;
-            this.locY = d1;
-            this.locZ = d2;
-            double d6 = (double) this.l();
-            double d7 = (double) this.m();
-            double d8 = (double) this.l();
+            double d6 = (double) width;
+            double d7 = (double) height;
+            double d8 = (double) width;
 
-            if (this.direction.k() == EnumDirection.EnumAxis.Z) {
+            if (direction.k() == EnumDirection.EnumAxis.Z) {
                 d8 = 1.0D;
             } else {
                 d6 = 1.0D;
@@ -62,7 +73,18 @@
             d6 /= 32.0D;
             d7 /= 32.0D;
             d8 /= 32.0D;
-            this.a(new AxisAlignedBB(d0 - d6, d1 - d7, d2 - d8, d0 + d6, d1 + d7, d2 + d8));
+            return new AxisAlignedBB(d0 - d6, d1 - d7, d2 - d8, d0 + d6, d1 + d7, d2 + d8);
+    }
+
+    private void updateBoundingBox() {
+        if (this.direction != null) {
+            // CraftBukkit start code moved in to calculateBoundingBox
+            AxisAlignedBB bb = calculateBoundingBox(this.blockPosition, this.direction, this.l(), this.m());
+            this.locX = (bb.a + bb.d) / 2.0D;
+            this.locY = (bb.b + bb.e) / 2.0D;
+            this.locZ = (bb.c + bb.f) / 2.0D;
+            this.a(bb);
+            // CraftBukkit end
         }
     }
 
@@ -77,6 +99,32 @@
         if (this.c++ == 100 && !this.world.isClientSide) {
             this.c = 0;
             if (!this.dead && !this.survives()) {
+                // CraftBukkit start - fire break events
+                Material material = this.world.getType(new BlockPosition(this)).getBlock().getMaterial();
+                HangingBreakEvent.RemoveCause cause;
+
+                if (!material.equals(Material.AIR)) {
+                    // TODO: This feels insufficient to catch 100% of suffocation cases
+                    cause = HangingBreakEvent.RemoveCause.OBSTRUCTION;
+                } else {
+                    cause = HangingBreakEvent.RemoveCause.PHYSICS;
+                }
+
+                HangingBreakEvent event = new HangingBreakEvent((Hanging) this.getBukkitEntity(), cause);
+                this.world.getServer().getPluginManager().callEvent(event);
+
+                PaintingBreakEvent paintingEvent = null;
+                if (this instanceof EntityPainting) {
+                    // Fire old painting event until it can be removed
+                    paintingEvent = new PaintingBreakEvent((Painting) this.getBukkitEntity(), PaintingBreakEvent.RemoveCause.valueOf(cause.name()));
+                    paintingEvent.setCancelled(event.isCancelled());
+                    this.world.getServer().getPluginManager().callEvent(paintingEvent);
+                }
+
+                if (dead || event.isCancelled() || (paintingEvent != null && paintingEvent.isCancelled())) {
+                    return;
+                }
+                // CraftBukkit end
                 this.die();
                 this.b((Entity) null);
             }
@@ -138,6 +186,32 @@
             return false;
         } else {
             if (!this.dead && !this.world.isClientSide) {
+                // CraftBukkit start - fire break events
+                HangingBreakEvent event = new HangingBreakEvent((Hanging) this.getBukkitEntity(), HangingBreakEvent.RemoveCause.DEFAULT);
+                PaintingBreakEvent paintingEvent = null;
+                if (damagesource.getEntity() != null) {
+                    event = new org.bukkit.event.hanging.HangingBreakByEntityEvent((Hanging) this.getBukkitEntity(), damagesource.getEntity() == null ? null : damagesource.getEntity().getBukkitEntity());
+
+                    if (this instanceof EntityPainting) {
+                        // Fire old painting event until it can be removed
+                        paintingEvent = new org.bukkit.event.painting.PaintingBreakByEntityEvent((Painting) this.getBukkitEntity(), damagesource.getEntity() == null ? null : damagesource.getEntity().getBukkitEntity());
+                    }
+                } else if (damagesource.isExplosion()) {
+                    event = new HangingBreakEvent((Hanging) this.getBukkitEntity(), HangingBreakEvent.RemoveCause.EXPLOSION);
+                }
+
+                this.world.getServer().getPluginManager().callEvent(event);
+
+                if (paintingEvent != null) {
+                    paintingEvent.setCancelled(event.isCancelled());
+                    this.world.getServer().getPluginManager().callEvent(paintingEvent);
+                }
+
+                if (this.dead || event.isCancelled() || (paintingEvent != null && paintingEvent.isCancelled())) {
+                    return true;
+                }
+                // CraftBukkit end
+
                 this.die();
                 this.ac();
                 this.b(damagesource.getEntity());
@@ -149,6 +223,18 @@
 
     public void move(double d0, double d1, double d2) {
         if (!this.world.isClientSide && !this.dead && d0 * d0 + d1 * d1 + d2 * d2 > 0.0D) {
+            if (this.dead) return; // CraftBukkit
+
+            // CraftBukkit start - fire break events
+            // TODO - Does this need its own cause? Seems to only be triggered by pistons
+            HangingBreakEvent event = new HangingBreakEvent((Hanging) this.getBukkitEntity(), HangingBreakEvent.RemoveCause.PHYSICS);
+            this.world.getServer().getPluginManager().callEvent(event);
+
+            if (this.dead || event.isCancelled()) {
+                return;
+            }
+            // CraftBukkit end
+
             this.die();
             this.b((Entity) null);
         }
@@ -156,7 +242,7 @@
     }
 
     public void g(double d0, double d1, double d2) {
-        if (!this.world.isClientSide && !this.dead && d0 * d0 + d1 * d1 + d2 * d2 > 0.0D) {
+        if (false && !this.world.isClientSide && !this.dead && d0 * d0 + d1 * d1 + d2 * d2 > 0.0D) { // CraftBukkit - not needed
             this.die();
             this.b((Entity) null);
         }