Apply source function after source mask in ForwardExtentCopy.

The source function should only get applied to actually copied blocks.

worldedit-core/src/main/java/com/sk89q/worldedit/EditSession.java

@@ -1252,7 +1252,7 @@ public class EditSession implements Extent, AutoCloseable {
         BlockVector3 to = region.getMinimumPoint();
 
         // Remove the original blocks
-        com.sk89q.worldedit.function.pattern.Pattern pattern = replacement != null ?
+        Pattern pattern = replacement != null ?
                 replacement :
                 new BlockPattern(BlockTypes.AIR.getDefaultState());
         BlockReplace remove = new BlockReplace(this, pattern);

worldedit-core/src/main/java/com/sk89q/worldedit/command/RegionCommands.java

@@ -262,11 +262,12 @@ public class RegionCommands {
     @Command(
         aliases = { "/move" },
         usage = "[count] [direction] [leave-id]",
-        flags = "s",
+        flags = "sa",
         desc = "Move the contents of the selection",
         help =
             "Moves the contents of the selection.\n" +
             "The -s flag shifts the selection to the target location.\n" +
+            "The -a flag skips air blocks.\n" +
             "Optionally fills the old location with <leave-id>.",
         min = 0,
         max = 3
@@ -278,9 +279,10 @@ public class RegionCommands {
                      @Optional("1") @Range(min = 1) int count,
                      @Optional(Direction.AIM) @Direction(includeDiagonals = true) BlockVector3 direction,
                      @Optional("air") Pattern replace,
-                     @Switch('s') boolean moveSelection) throws WorldEditException {
+                     @Switch('s') boolean moveSelection,
+                     @Switch('a') boolean ignoreAirBlocks) throws WorldEditException {
 
-        int affected = editSession.moveRegion(region, direction, count, true, replace);
+        int affected = editSession.moveRegion(region, direction, count, !ignoreAirBlocks, replace);
 
         if (moveSelection) {
             try {

worldedit-core/src/main/java/com/sk89q/worldedit/function/operation/ForwardExtentCopy.java

@@ -248,9 +248,9 @@ public class ForwardExtentCopy implements Operation {
             }
 
             ExtentBlockCopy blockCopy = new ExtentBlockCopy(source, from, destination, to, currentTransform);
-            RegionMaskingFilter filter = new RegionMaskingFilter(sourceMask, blockCopy);
-            RegionFunction function = sourceFunction != null ? new CombinedRegionFunction(filter, sourceFunction) : filter;
-            RegionVisitor blockVisitor = new RegionVisitor(region, function);
+            RegionMaskingFilter filteredFunction = new RegionMaskingFilter(sourceMask,
+                    sourceFunction == null ? blockCopy : new CombinedRegionFunction(blockCopy, sourceFunction));
+            RegionVisitor blockVisitor = new RegionVisitor(region, filteredFunction);
 
             lastVisitor = blockVisitor;