added missing case for `AT_DRAIN_EXP' (bug 1514).

added assert that triggers if a unit has no faction.

core/src/gamecode/laws.c

@@ -2616,6 +2616,7 @@ static bool display_race(faction * f, unit * u, const race * rc)
       case AT_SPELL:
       case AT_COMBATSPELL:
       case AT_DRAIN_ST:
+      case AT_DRAIN_EXP:
       case AT_DAZZLE:
         bytes = snprintf(bufp, size, "%s", LOC(f->locale, "attack_magical"));
         break;

core/src/kernel/unit.c

@@ -225,6 +225,7 @@ int gift_items(unit * u, int flags)
   int rule = rule_give();
 
   assert(u->region);
+  assert(u->faction);
 
   if ((u->faction->flags & FFL_QUIT) == 0 || (rule & GIVE_ONDEATH) == 0) {
     if ((rule & GIVE_ALLITEMS) == 0 && (flags & GIFT_FRIENDS))