--- ../src-base/minecraft/net/minecraft/block/BlockPistonBase.java
+++ ../src-work/minecraft/net/minecraft/block/BlockPistonBase.java
@@ -21,6 +21,12 @@
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.block.CraftBlock;
+import org.bukkit.event.block.BlockPistonRetractEvent;
+import org.bukkit.event.block.BlockPistonExtendEvent;
+// CraftBukkit end
+
 public class BlockPistonBase extends Block
 {
     private final boolean isSticky;
@@ -128,13 +134,37 @@
 
             if (flag && !isExtended(l))
             {
-                if (canExtend(p_150078_1_, p_150078_2_, p_150078_3_, p_150078_4_, i1))
+                // CraftBukkit start
+                int length = canExtend_IntCB(p_150078_1_, p_150078_2_, p_150078_3_, p_150078_4_, i1);
+
+                if (length >= 0)
                 {
+                    org.bukkit.block.Block block = p_150078_1_.getWorld().getBlockAt(p_150078_2_, p_150078_3_, p_150078_4_);
+                    BlockPistonExtendEvent event = new BlockPistonExtendEvent(block, length, CraftBlock.notchToBlockFace(i1));
+                    p_150078_1_.getServer().getPluginManager().callEvent(event);
+
+                    if (event.isCancelled())
+                    {
+                        return;
+                    }
+
+                    // CraftBukkit end
                     p_150078_1_.addBlockEvent(p_150078_2_, p_150078_3_, p_150078_4_, this, 0, i1);
                 }
             }
             else if (!flag && isExtended(l))
             {
+                // CraftBukkit start
+                org.bukkit.block.Block block = p_150078_1_.getWorld().getBlockAt(p_150078_2_, p_150078_3_, p_150078_4_);
+                BlockPistonRetractEvent event = new BlockPistonRetractEvent(block, CraftBlock.notchToBlockFace(i1));
+                p_150078_1_.getServer().getPluginManager().callEvent(event);
+
+                if (event.isCancelled())
+                {
+                    return;
+                }
+
+                // CraftBukkit end
                 p_150078_1_.setBlockMetadataWithNotify(p_150078_2_, p_150078_3_, p_150078_4_, i1, 2);
                 p_150078_1_.addBlockEvent(p_150078_2_, p_150078_3_, p_150078_4_, this, 1, i1);
             }
@@ -297,6 +327,11 @@
 
     public static int getPistonOrientation(int p_150076_0_)
     {
+        if ((p_150076_0_ & 7) >= Facing.oppositeSide.length)
+        {
+            return 7;    // CraftBukkit - check for AIOOB on piston data
+        }
+
         return p_150076_0_ & 7;
     }
 
@@ -366,7 +401,13 @@
         }
     }
 
-    private static boolean canExtend(World p_150077_0_, int p_150077_1_, int p_150077_2_, int p_150077_3_, int p_150077_4_)
+    // Cauldron start - vanilla compatibility
+    private static boolean canExtend(World world, int i, int j, int k, int l) {
+        return canExtend_IntCB(world, i, j, k, l) >= 0;
+    }
+    // Cauldron end
+
+    private static int canExtend_IntCB(World p_150077_0_, int p_150077_1_, int p_150077_2_, int p_150077_3_, int p_150077_4_) // CraftBukkit int -> boolean
     {
         int i1 = p_150077_1_ + Facing.offsetsXForSide[p_150077_4_];
         int j1 = p_150077_2_ + Facing.offsetsYForSide[p_150077_4_];
@@ -379,7 +420,7 @@
             {
                 if (j1 <= 0 || j1 >= p_150077_0_.getHeight())
                 {
-                    return false;
+                    return -1; // CraftBukkit
                 }
 
                 Block block = p_150077_0_.getBlock(i1, j1, k1);
@@ -388,14 +429,14 @@
                 {
                     if (!canPushBlock(block, p_150077_0_, i1, j1, k1, true))
                     {
-                        return false;
+                        return -1; // CraftBukkit
                     }
 
                     if (block.getMobilityFlag() != 1)
                     {
                         if (l1 == 12)
                         {
-                            return false;
+                            return -1; // CraftBukkit
                         }
 
                         i1 += Facing.offsetsXForSide[p_150077_4_];
@@ -407,7 +448,7 @@
                 }
             }
 
-            return true;
+            return l1; // CraftBukkit
         }
     }
 
