From ca7579e0a7446ac45f5f16878ed90dde1e8c2fbc Mon Sep 17 00:00:00 2001
From: SirYwell <hannesgreule@outlook.de>
Date: Sat, 17 Feb 2018 03:56:07 +0100
Subject: [PATCH] fixec //overlay command where the bottom layer was set to the
 given block even if the block below is air

---
 .../object/function/SurfaceRegionFunction.java    |  2 +-
 .../java/com/sk89q/worldedit/extent/Extent.java   | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/core/src/main/java/com/boydti/fawe/object/function/SurfaceRegionFunction.java b/core/src/main/java/com/boydti/fawe/object/function/SurfaceRegionFunction.java
index 0a4f7229..8858d302 100644
--- a/core/src/main/java/com/boydti/fawe/object/function/SurfaceRegionFunction.java
+++ b/core/src/main/java/com/boydti/fawe/object/function/SurfaceRegionFunction.java
@@ -27,7 +27,7 @@ public class SurfaceRegionFunction implements FlatRegionFunction {
     public boolean apply(Vector2D position) throws WorldEditException {
         int x = position.getBlockX();
         int z = position.getBlockZ();
-        int layer = extent.getNearestSurfaceTerrainBlock(x, z, lastY, minY, maxY);
+        int layer = extent.getNearestSurfaceTerrainBlock(x, z, lastY, minY, maxY, false);
         if (layer != -1) {
             lastY = layer;
             return function.apply(mutable.setComponents(x, layer, z));
diff --git a/core/src/main/java/com/sk89q/worldedit/extent/Extent.java b/core/src/main/java/com/sk89q/worldedit/extent/Extent.java
index a80e7b8b..73c5f380 100644
--- a/core/src/main/java/com/sk89q/worldedit/extent/Extent.java
+++ b/core/src/main/java/com/sk89q/worldedit/extent/Extent.java
@@ -122,11 +122,19 @@ public interface Extent extends InputExtent, OutputExtent {
         return (state ? minY : maxY) << 4;
     }
 
+    public default int getNearestSurfaceTerrainBlock(int x, int z, int y, int minY, int maxY, boolean ignoreAir) {
+        return getNearestSurfaceTerrainBlock(x, z, y, minY, maxY, minY, maxY, ignoreAir);
+    }
+
     public default int getNearestSurfaceTerrainBlock(int x, int z, int y, int minY, int maxY) {
         return getNearestSurfaceTerrainBlock(x, z, y, minY, maxY, minY, maxY);
     }
 
     public default int getNearestSurfaceTerrainBlock(int x, int z, int y, int minY, int maxY, int failedMin, int failedMax) {
+        return getNearestSurfaceTerrainBlock(x, z, y, minY, maxY, failedMin, failedMax, true);
+    }
+
+    public default int getNearestSurfaceTerrainBlock(int x, int z, int y, int minY, int maxY, int failedMin, int failedMax, boolean ignoreAir) {
         y = Math.max(minY, Math.min(maxY, y));
         int clearanceAbove = maxY - y;
         int clearanceBelow = y - minY;
@@ -155,7 +163,12 @@ public interface Extent extends InputExtent, OutputExtent {
                 }
             }
         }
-        return state ? failedMin : failedMax;
+        int result = state ? failedMin : failedMax;
+        if(result > 0 && !ignoreAir) {
+            block = getLazyBlock(x, result, z);
+            return block.isAir() ? -1 : result;
+        }
+        return result;
     }
 
     default public void addCaves(Region region) throws WorldEditException {