Multithreading crash fixes / Server 'find' command added

core/src/io/anuke/mindustry/core/World.java

@@ -244,7 +244,7 @@ public class World extends Module{
 			Array<Tile> removals = target.getLinkedTiles();
 			for(Tile toremove : removals){
 				//note that setting a new block automatically unlinks it
-				toremove.setBlock(Blocks.air);
+				if(toremove != null) toremove.setBlock(Blocks.air);
 			}
 		}
 	}

core/src/io/anuke/mindustry/net/Administration.java

@@ -172,6 +172,18 @@ public class Administration {
         return info.admin && ip.equals(info.validAdminIP);
     }
 
+    public Array<PlayerInfo> findByName(String name, boolean last){
+        Array<PlayerInfo> result = new Array<>();
+
+        for(PlayerInfo info : playerInfo.values()){
+            if(info.lastName.toLowerCase().equals(name.toLowerCase()) || (last && info.names.contains(name, false))){
+                result.add(info);
+            }
+        }
+
+        return result;
+    }
+
     public PlayerInfo getInfo(String id){
         return getCreateInfo(id);
     }

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

@@ -106,13 +106,18 @@ public class Placement {
         rect.setCenter(offset.x + x * tilesize, offset.y + y * tilesize);
 
         synchronized (Entities.entityLock) {
-            for (SolidEntity e : Entities.getNearby(enemyGroup, x * tilesize, y * tilesize, tilesize * 2f)) {
-                if (e == null) continue; //not sure why this happens?
-                Rectangle rect = e.hitbox.getRect(e.x, e.y);
+            //exception sometimes thrown due to multithreading, not sure what else to try at this point
+            try {
+                for (SolidEntity e : Entities.getNearby(enemyGroup, x * tilesize, y * tilesize, tilesize * 2f)) {
+                    if (e == null) continue; //not sure why this happens?
+                    Rectangle rect = e.hitbox.getRect(e.x, e.y);
 
-                if (Placement.rect.overlaps(rect)) {
-                    return false;
+                    if (Placement.rect.overlaps(rect)) {
+                        return false;
+                    }
                 }
+            }catch (Exception e){
+                return false;
             }
         }