Before rP19655, after the ai had send some soldiers to attack a cc in construction around its territory and has killed all enemy builders, it lost control of its soldiers which were then directed by UnitAI to destroy the cc.
After rP19655, the ai keep control but stupidly retreat once all builders are killed without destroying the enemy cc foundation as he is not aware of the presence of this foundation.
This patch fixes that, by looking for any such target before retreating and creating a special attack to destroy it.