Some minor cleanup

core/src/io/anuke/mindustry/input/DesktopInput.java

@@ -182,7 +182,7 @@ public class DesktopInput extends InputHandler{
             mode = none;
         }
 
-        if(mode == placing || isPlacing()){
+        if(mode != none || isPlacing()){
             selectRequests.clear();
             lastSchematic = null;
         }
@@ -365,7 +365,6 @@ public class DesktopInput extends InputHandler{
 
             if(!selectRequests.isEmpty()){
                 flushRequests(selectRequests);
-                //selectRequests.clear();
             }else if(isPlacing()){
                 selectX = cursorX;
                 selectY = cursorY;

core/src/io/anuke/mindustry/world/Tile.java

@@ -123,15 +123,15 @@ public class Tile implements Position, TargetTrait{
         return block().solid && !block().synthetic() && block().fillsTile;
     }
 
-    public Floor floor(){
+    public @NonNull Floor floor(){
         return floor;
     }
 
-    public Block block(){
+    public @NonNull Block block(){
         return block;
     }
 
-    public Floor overlay(){
+    public @NonNull Floor overlay(){
         return overlay;
     }