Paper/nms-patches/BlockButtonAbstract.patch

--- a/net/minecraft/server/BlockButtonAbstract.java
+++ b/net/minecraft/server/BlockButtonAbstract.java
@@ -4,6 +4,11 @@
 import java.util.Random;
 import javax.annotation.Nullable;
 
+// CraftBukkit start
+import org.bukkit.event.block.BlockRedstoneEvent;
+import org.bukkit.event.entity.EntityInteractEvent;
+// CraftBukkit end
+
 public abstract class BlockButtonAbstract extends BlockDirectional {
 
     public static final BlockStateBoolean POWERED = BlockStateBoolean.of("powered");
@@ -126,6 +131,19 @@
         if (((Boolean) iblockdata.get(BlockButtonAbstract.POWERED)).booleanValue()) {
             return true;
         } else {
+            // CraftBukkit start
+            boolean powered = ((Boolean) iblockdata.get(POWERED));
+            org.bukkit.block.Block block = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
+            int old = (powered) ? 15 : 0;
+            int current = (!powered) ? 15 : 0;
+
+            BlockRedstoneEvent eventRedstone = new BlockRedstoneEvent(block, old, current);
+            world.getServer().getPluginManager().callEvent(eventRedstone);
+
+            if ((eventRedstone.getNewCurrent() > 0) != (!powered)) {
+                return true;
+            }
+            // CraftBukkit end
             world.setTypeAndData(blockposition, iblockdata.set(BlockButtonAbstract.POWERED, Boolean.valueOf(true)), 3);
             world.b(blockposition, blockposition);
             this.a(entityhuman, world, blockposition);
@@ -167,6 +185,16 @@
                 if (this.I) {
                     this.d(iblockdata, world, blockposition);
                 } else {
+                    // CraftBukkit start
+                    org.bukkit.block.Block block = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
+
+                    BlockRedstoneEvent eventRedstone = new BlockRedstoneEvent(block, 15, 0);
+                    world.getServer().getPluginManager().callEvent(eventRedstone);
+
+                    if (eventRedstone.getNewCurrent() > 0) {
+                        return;
+                    }
+                    // CraftBukkit end
                     world.setTypeUpdate(blockposition, iblockdata.set(BlockButtonAbstract.POWERED, Boolean.valueOf(false)));
                     this.c(world, blockposition, (EnumDirection) iblockdata.get(BlockButtonAbstract.FACING));
                     this.b(world, blockposition);
@@ -192,7 +220,41 @@
         boolean flag = !list.isEmpty();
         boolean flag1 = ((Boolean) iblockdata.get(BlockButtonAbstract.POWERED)).booleanValue();
 
+        // CraftBukkit start - Call interact event when arrows turn on wooden buttons
+        if (flag1 != flag && flag) {
+            org.bukkit.block.Block block = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
+            boolean allowed = false;
+
+            // If all of the events are cancelled block the button press, else allow
+            for (Object object : list) {
+                if (object != null) {
+                    EntityInteractEvent event = new EntityInteractEvent(((Entity) object).getBukkitEntity(), block);
+                    world.getServer().getPluginManager().callEvent(event);
+
+                    if (!event.isCancelled()) {
+                        allowed = true;
+                        break;
+                    }
+                }
+            }
+
+            if (!allowed) {
+                return;
+            }
+        }
+        // CraftBukkit end
+
         if (flag && !flag1) {
+            // CraftBukkit start
+            org.bukkit.block.Block block = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
+
+            BlockRedstoneEvent eventRedstone = new BlockRedstoneEvent(block, 0, 15);
+            world.getServer().getPluginManager().callEvent(eventRedstone);
+
+            if (eventRedstone.getNewCurrent() <= 0) {
+                return;
+            }
+            // CraftBukkit end
             world.setTypeUpdate(blockposition, iblockdata.set(BlockButtonAbstract.POWERED, Boolean.valueOf(true)));
             this.c(world, blockposition, (EnumDirection) iblockdata.get(BlockButtonAbstract.FACING));
             world.b(blockposition, blockposition);
@@ -200,6 +262,16 @@
         }
 
         if (!flag && flag1) {
+            // CraftBukkit start
+            org.bukkit.block.Block block = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
+
+            BlockRedstoneEvent eventRedstone = new BlockRedstoneEvent(block, 15, 0);
+            world.getServer().getPluginManager().callEvent(eventRedstone);
+
+            if (eventRedstone.getNewCurrent() > 0) {
+                return;
+            }
+            // CraftBukkit end
             world.setTypeUpdate(blockposition, iblockdata.set(BlockButtonAbstract.POWERED, Boolean.valueOf(false)));
             this.c(world, blockposition, (EnumDirection) iblockdata.get(BlockButtonAbstract.FACING));
             world.b(blockposition, blockposition);