[wesnoth-commits] [wesnoth/wesnoth] ae4e3f: AI: fix crash when using attacks aspect

[mattsc]

  Branch: refs/heads/master
  Home:   https://github.com/wesnoth/wesnoth
  Commit: ae4e3f2191b9e7ac675ee9c6f79491ca7c208c44
      https://github.com/wesnoth/wesnoth/commit/ae4e3f2191b9e7ac675ee9c6f79491ca7c208c44
  Author: mattsc <mattsc000 at gmail.com>
  Date:   2021-06-17 (Thu, 17 Jun 2021)

  Changed paths:
    M src/ai/default/ca.cpp

  Log Message:
  -----------
  AI: fix crash when using attacks aspect

When the attacks aspect is used with invalidate_on_gamestate_change set to no, its movements field may point to locations without units if those units moved during a previous attack.  Thus, we need to check whether u contains a valid unit.

Fixes #5865