Yet another segfault (a.k.a. Darkhog is a total noob)

[wagenheimer]

Are you sure CurrentSprite is a valid index?

You should not do this, , but try this, it will avoid anything wrong :

function TGameObject.isColliding(Sprite: TSprite): Boolean;
begin
  Result:=false; //setting result, just in case

  if (not Assigned(self)) or (not Assigned(Sprite)) then Exit;

  case ObjectMode of
    omAnim:   begin
                if (CurrentAnim>0) and (CurrentAnim<=Animations.Items.Count-1) then
                if Assigned(Animations.Items[CurrentAnim]) then //safety check so we won't get segfault
                  //setting result
                  Result:=Animations.Items[CurrentAnim].IsColliding(Sprite);
                end;
    omSprite: begin
                if (CurrentSprite>0) and (CurrentSprite<=Animations.Items.Count-1) then
                if Sprites.Items[CurrentSprite]<>nil then //safety check so we won't get segfault
                  //setting result
                  Result:=Sprites.Items[CurrentSprite].IsColliding(Sprite);
              end;
  end;
end;