[Freeciv-Dev] (PR#11227) AI Hunters Pessimistic about Missile Effectiveness (dangling ptr)

["Benedict Adamson" <badamson@xxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=11227 >

The ai_hunter_manage function tries launching missiles at its target, 
using ai_hunter_try_launch. It also tries directly attacking the target, 
by moving towards the target, using ai_unit_goto and then 
ai_unit_attack. It tries the missile attack before the direct attack.

However, it assumes that the target still exists when computing the 
direct attack; that is, it assumes the missile attack fails. The code 
unfortunately retains a pointer to the target, which is then a dangling 
pointer and can cause a crash.