Fixes #881 and lets vampires gain nutrition from consuming blood reagent.

Fixes #881, vampires should no longer get fat from drinking too much blood. Handle_blood now checks for blood that isn't their own and "eats" it.

code/game/gamemodes/vampire/vampire.dm

@@ -293,7 +293,7 @@ You are weak to holy things and starlight. Don't go into space and avoid the Cha
 		H.vessel.remove_reagent("blood",25)
 		if(ishuman(src))
 			var/mob/living/carbon/human/V = src
-			V.nutrition += blood
+			V.nutrition = min(450,V.nutrition+(blood/2))
 
 	src.mind.vampire.draining = null
 	src << "\blue You stop draining [H.name] of blood."

code/modules/organs/blood.dm

@@ -61,6 +61,19 @@ var/const/BLOOD_VOLUME_SURVIVE = 122
 			if(blood_volume < 560 && blood_volume)
 				var/datum/reagent/blood/B = locate() in vessel.reagent_list //Grab some blood
 				if(B) // Make sure there's some blood at all
+
+					if(src.mind) //Handles vampires "eating" blood that isn't their own.
+						if(src.mind in ticker.mode.vampires)
+							for(var/datum/reagent/blood/BL in vessel.reagent_list)
+								if(src.nutrition >= 450)
+									break //We don't want blood tranfusions making vampires fat.
+								if(BL.data["donor"] != src)
+									src.nutrition += (15 * REAGENTS_METABOLISM)
+									BL.volume -= REAGENTS_METABOLISM
+									if(BL.volume <= 0)
+										del(BL)
+									break //Only process one blood per tick, to maintain the same metabolism as nutriment for non-vampires.
+
 					if(B.data["donor"] != src) //If it's not theirs, then we look for theirs
 						for(var/datum/reagent/blood/D in vessel.reagent_list)
 							if(D.data["donor"] == src)

code/modules/reagents/Chemistry-Reagents.dm

@@ -1486,9 +1486,9 @@ datum
 
 			on_mob_life(var/mob/living/M as mob)
 				if(!M) M = holder.my_atom
-				if(prob(50)) M.heal_organ_damage(1,0)
 				if(!(M.mind in ticker.mode.vampires))
 					M.nutrition += nutriment_factor	// For hunger and fatness
+					if(prob(50)) M.heal_organ_damage(1,0)
 				..()
 				return