[starvingdead] vanish the undead instead of marking them inactive

changelog.txt

@@ -34,6 +34,7 @@ Template for new versions:
 - `caravan`: Correct price adjustment values in trade agreement details screen
 - `caravan`: Apply both import and export trade agreement price adjustments to items being both bought or sold to align with how vanilla DF calculates prices
 - `suspendmanager`: Improve the detection on "T" and "+" shaped high walls
+- `starvingdead`: ensure sieges end properly when undead siegers starve
 
 ## Misc Improvements
 - `devel/lsmem`: added support for filtering by memory addresses and filenames

starvingdead.lua

@@ -45,35 +45,30 @@ end
 StarvingDead = defclass(StarvingDead)
 StarvingDead.ATTRS{
   decay_rate = 1,
-  death_threshold = 6
+  death_threshold = 6,
 }
 
 function StarvingDead:init()
   self.timeout_id = nil
   -- Percentage goal each attribute should reach before death.
-  self.attribute_goal = 10
-  self.attribute_decay = (self.attribute_goal ^ (1 / ((self.death_threshold * 28 / self.decay_rate)))) / 100
-  self.undead_count = 0
+  local attribute_goal = 10
+  self.attribute_decay = (attribute_goal ^ (1 / ((self.death_threshold * 28 / self.decay_rate)))) / 100
 
   self:checkDecay()
   print(([[StarvingDead started, checking every %s days and killing off at %s months]]):format(self.decay_rate, self.death_threshold))
 end
 
 function StarvingDead:checkDecay()
-  self.undead_count = 0
   for _, unit in pairs(df.global.world.units.active) do
     if (unit.enemy.undead and not unit.flags1.inactive) then
-      self.undead_count = self.undead_count + 1
-
       -- time_on_site is measured in ticks, a month is 33600 ticks.
       -- @see https://dwarffortresswiki.org/index.php/Time
       for _, attribute in pairs(unit.body.physical_attrs) do
         attribute.value = math.floor(attribute.value - (attribute.value * self.attribute_decay))
       end
 
       if unit.curse.time_on_site > (self.death_threshold * 33600) then
-        unit.flags1.inactive = true
-        unit.curse.rem_tags2.FIT_FOR_ANIMATION = true
+        unit.animal.vanish_countdown = 1
       end
     end
   end