PaperMC/nms-patches/BlockCommand.patch

--- /home/matt/mc-dev-private//net/minecraft/server/BlockCommand.java	2015-02-26 22:40:22.071608145 +0000
+++ src/main/java/net/minecraft/server/BlockCommand.java	2015-02-26 22:40:22.071608145 +0000
@@ -2,6 +2,8 @@
 
 import java.util.Random;
 
+import org.bukkit.event.block.BlockRedstoneEvent; // CraftBukkit
+
 public class BlockCommand extends BlockContainer {
 
     public static final BlockStateBoolean TRIGGERED = BlockStateBoolean.of("triggered");
@@ -20,10 +22,19 @@
             boolean flag = world.isBlockIndirectlyPowered(blockposition);
             boolean flag1 = ((Boolean) iblockdata.get(BlockCommand.TRIGGERED)).booleanValue();
 
-            if (flag && !flag1) {
+            // CraftBukkit start
+            org.bukkit.block.Block bukkitBlock = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
+            int old = flag1 ? 15 : 0;
+            int current = flag ? 15 : 0;
+
+            BlockRedstoneEvent eventRedstone = new BlockRedstoneEvent(bukkitBlock, old, current);
+            world.getServer().getPluginManager().callEvent(eventRedstone);
+            // CraftBukkit end
+
+            if (eventRedstone.getNewCurrent() > 0 && !(eventRedstone.getOldCurrent() > 0)) { // CraftBukkit
                 world.setTypeAndData(blockposition, iblockdata.set(BlockCommand.TRIGGERED, Boolean.valueOf(true)), 4);
                 world.a(blockposition, (Block) this, this.a(world));
-            } else if (!flag && flag1) {
+            } else if (!(eventRedstone.getNewCurrent() > 0) && eventRedstone.getOldCurrent() > 0) { // CraftBukkit
                 world.setTypeAndData(blockposition, iblockdata.set(BlockCommand.TRIGGERED, Boolean.valueOf(false)), 4);
             }
         }