Program: 41400
Project: 41400
Buggy source:
@SuppressWarnings("String_Node_Str") @EventHandler(priority=EventPriority.MONITOR,ignoreCancelled=true) public void slabInteract(PlayerInteractEvent event){
  if (event.getItem() == null) {
    return;
  }
  if (event.getItem().getType().toString().equals("String_Node_Str")) {
    if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
      if (event.getClickedBlock().getState().getData().toString().equals("String_Node_Str")) {
        if (event.getBlockFace().toString().equals("String_Node_Str")) {
          event.getClickedBlock().setType(Carbon.injector().redSandstoneDoubleSlabMat);
          if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
            event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
          }
          event.setCancelled(true);
        }
      }
      if (event.getClickedBlock().getState().getData().toString().equals("String_Node_Str")) {
        if (event.getBlockFace().toString().equals("String_Node_Str")) {
          event.getClickedBlock().setType(Carbon.injector().redSandstoneDoubleSlabMat);
          event.getClickedBlock().setData((byte)0);
          if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
            event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
          }
          event.setCancelled(true);
        }
      }
      org.bukkit.block.Block block=event.getClickedBlock();
switch (event.getBlockFace().toString()) {
case "String_Node_Str":
{
          org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY(),block.getZ() - 1);
          if (adjacent.getType().toString().equals("String_Node_Str")) {
            adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
            adjacent.setData((byte)0);
            if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
              event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
            }
            event.setCancelled(true);
          }
        }
case "String_Node_Str":
{
        org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY(),block.getZ() + 1);
        if (adjacent.getType().toString().equals("String_Node_Str")) {
          adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
          adjacent.setData((byte)0);
          if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
            event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
          }
          event.setCancelled(true);
        }
      }
case "String_Node_Str":
{
      org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX() - 1,block.getY(),block.getZ());
      if (adjacent.getType().toString().equals("String_Node_Str")) {
        adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
        adjacent.setData((byte)0);
        if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
          event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
        }
        event.setCancelled(true);
      }
    }
case "String_Node_Str":
{
    org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX() + 1,block.getY(),block.getZ());
    if (adjacent.getType().toString().equals("String_Node_Str")) {
      adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
      adjacent.setData((byte)0);
      if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
        event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
      }
      event.setCancelled(true);
    }
  }
case "String_Node_Str":
{
  org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY() - 1,block.getZ());
  if (adjacent.getType().toString().equals("String_Node_Str")) {
    adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
    adjacent.setData((byte)0);
    if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
      event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
    }
    event.setCancelled(true);
  }
}
case "String_Node_Str":
{
org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY() + 1,block.getZ());
if (adjacent.getType().toString().equals("String_Node_Str")) {
  adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
  adjacent.setData((byte)0);
  if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
    event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
  }
  event.setCancelled(true);
}
}
}
}
}
}

Fixed version (ground truth):
@SuppressWarnings("String_Node_Str") @EventHandler(priority=EventPriority.MONITOR,ignoreCancelled=true) public void slabInteract(PlayerInteractEvent event){
  if (event.getItem() == null) {
    return;
  }
  if (event.getItem().getType().toString().equals("String_Node_Str")) {
    if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
      if (event.getClickedBlock().getState().getData().toString().equals("String_Node_Str")) {
        if (event.getBlockFace().toString().equals("String_Node_Str")) {
          event.getClickedBlock().setType(Carbon.injector().redSandstoneDoubleSlabMat);
          if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
            event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
          }
          event.setCancelled(true);
        }
      }
      if (event.getClickedBlock().getState().getData().toString().equals("String_Node_Str")) {
        if (event.getBlockFace().toString().equals("String_Node_Str")) {
          event.getClickedBlock().setType(Carbon.injector().redSandstoneDoubleSlabMat);
          event.getClickedBlock().setData((byte)0);
          if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
            event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
          }
          event.setCancelled(true);
        }
      }
      org.bukkit.block.Block block=event.getClickedBlock();
switch (event.getBlockFace().toString()) {
case "String_Node_Str":
{
          org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY(),block.getZ() - 1);
          if (adjacent.getType().toString().equals("String_Node_Str")) {
            adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
            adjacent.setData((byte)0);
            if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
              event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
            }
            event.setCancelled(true);
          }
          break;
        }
case "String_Node_Str":
{
        org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY(),block.getZ() + 1);
        if (adjacent.getType().toString().equals("String_Node_Str")) {
          adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
          adjacent.setData((byte)0);
          if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
            event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
          }
          event.setCancelled(true);
        }
        break;
      }
case "String_Node_Str":
{
      org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX() - 1,block.getY(),block.getZ());
      if (adjacent.getType().toString().equals("String_Node_Str")) {
        adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
        adjacent.setData((byte)0);
        if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
          event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
        }
        event.setCancelled(true);
      }
      break;
    }
case "String_Node_Str":
{
    org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX() + 1,block.getY(),block.getZ());
    if (adjacent.getType().toString().equals("String_Node_Str")) {
      adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
      adjacent.setData((byte)0);
      if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
        event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
      }
      event.setCancelled(true);
    }
    break;
  }
case "String_Node_Str":
{
  org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY() - 1,block.getZ());
  if (adjacent.getType().toString().equals("String_Node_Str")) {
    adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
    adjacent.setData((byte)0);
    if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
      event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
    }
    event.setCancelled(true);
  }
  break;
}
case "String_Node_Str":
{
org.bukkit.block.Block adjacent=block.getWorld().getBlockAt(block.getX(),block.getY() + 1,block.getZ());
if (adjacent.getType().toString().equals("String_Node_Str")) {
  adjacent.setType(Carbon.injector().redSandstoneDoubleSlabMat);
  adjacent.setData((byte)0);
  if (event.getPlayer().getGameMode() != GameMode.CREATIVE) {
    event.getPlayer().getItemInHand().setAmount(event.getPlayer().getItemInHand().getAmount() - 1);
  }
  event.setCancelled(true);
}
break;
}
}
}
}
}