v2.0.0: fixed challenge having no text if targeting an empty space

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/hero/abilities/duelist/Challenge.java

@@ -81,19 +81,21 @@ public class Challenge extends ArmorAbility {
 
 	@Override
 	protected void activate(ClassArmor armor, Hero hero, Integer target) {
-		if (target == null || !Dungeon.level.heroFOV[target]){
+		if (target == null){
 			return;
 		}
 
 		Char targetCh = Actor.findChar(target);
+		if (targetCh == null || !Dungeon.level.heroFOV[target]){
+			GLog.w(Messages.get(this, "no_target"));
+			return;
+		}
 
 		if (hero.buff(DuelParticipant.class) != null){
 			GLog.w(Messages.get(this, "already_dueling"));
 			return;
 		}
 
-		if (targetCh != null){
-
 		if (targetCh.alignment == hero.alignment){
 			GLog.w(Messages.get(this, "ally_target"));
 			return;
@@ -180,7 +182,6 @@ public class Challenge extends ArmorAbility {
 			hero.buff(EliminationMatchTracker.class).detach();
 		}
 	}
-	}
 
 	@Override
 	public Talent[] talents() {