Refactors virus spreading

code/game/objects/effects/decals/cleanable.dm

@@ -6,7 +6,7 @@
 	var/bloodiness = 0 //0-100, amount of blood in this decal, used for making footprints and affecting the alpha of bloody footprints
 	var/mergeable_decal = 1 //when two of these are on a same tile or do we need to merge them into just one?
 
-/obj/effect/decal/cleanable/Initialize(mapload)
+/obj/effect/decal/cleanable/Initialize(mapload, list/datum/disease/diseases)
 	if (random_icon_states && length(src.random_icon_states) > 0)
 		src.icon_state = pick(src.random_icon_states)
 	create_reagents(300)
@@ -14,10 +14,15 @@
 		for(var/obj/effect/decal/cleanable/C in src.loc)
 			if(C != src && C.type == src.type)
 				replace_decal(C)
+	if(LAZYLEN(diseases))
+		var/list/datum/disease/diseases_to_add = list()
+		for(var/datum/disease/D in diseases)
+			if(D.spread_flags & VIRUS_SPREAD_CONTACT_FLUIDS)
+				diseases_to_add += D
+		if(LAZYLEN(diseases_to_add))
+			AddComponent(/datum/component/infective, diseases_to_add)
 	. = ..()
 
-
-
 /obj/effect/decal/cleanable/proc/replace_decal(obj/effect/decal/cleanable/C)
 	if(mergeable_decal)
 		qdel(C)
@@ -65,6 +70,7 @@
 //Add "bloodiness" of this blood's type, to the human's shoes
 //This is on /cleanable because fuck this ancient mess
 /obj/effect/decal/cleanable/Crossed(atom/movable/O)
+	..()
 	if(ishuman(O))
 		var/mob/living/carbon/human/H = O
 		if(H.shoes && blood_state && bloodiness)

code/game/objects/effects/decals/cleanable/humans.dm

@@ -18,7 +18,7 @@
 	desc = "Looks like it's been here a while.  Eew."
 	bloodiness = 0
 
-/obj/effect/decal/cleanable/blood/old/Initialize()
+/obj/effect/decal/cleanable/blood/old/Initialize(mapload, list/datum/disease/diseases)
 	. = ..()
 	icon_state += "-old" //This IS necessary because the parent /blood type uses icon randomization.
 	blood_DNA["Non-human DNA"] = "A+"
@@ -39,7 +39,6 @@
 	var/list/existing_dirs = list()
 	blood_DNA = list()
 
-
 /obj/effect/decal/cleanable/trail_holder/can_bloodcrawl_in()
 	return 1
 
@@ -53,7 +52,7 @@
 	random_icon_states = list("gib1", "gib2", "gib3", "gib4", "gib5", "gib6")
 	mergeable_decal = 0
 
-/obj/effect/decal/cleanable/blood/gibs/Initialize()
+/obj/effect/decal/cleanable/blood/gibs/Initialize(mapload, list/datum/disease/diseases)
 	. = ..()
 	reagents.add_reagent("liquidgibs", 5)
 
@@ -66,7 +65,11 @@
 	for(var/i = 0, i < pick(1, 200; 2, 150; 3, 50), i++)
 		sleep(2)
 		if(i > 0)
-			new /obj/effect/decal/cleanable/blood/splatter(loc)
+			var/list/datum/disease/diseases
+			GET_COMPONENT(infective, /datum/component/infective)
+			if(infective)
+				diseases = infective.diseases
+			new /obj/effect/decal/cleanable/blood/splatter(loc, diseases)
 		if(!step_to(src, get_step(src, direction), 0))
 			break
 
@@ -93,7 +96,7 @@
 	desc = "Space Jesus, why didn't anyone clean this up?  It smells terrible."
 	bloodiness = 0
 
-/obj/effect/decal/cleanable/blood/gibs/old/Initialize()
+/obj/effect/decal/cleanable/blood/gibs/old/Initialize(mapload, list/datum/disease/diseases)
 	. = ..()
 	setDir(pick(1,2,4,8))
 	icon_state += "-old"
@@ -126,6 +129,7 @@
 	var/list/shoe_types = list()
 
 /obj/effect/decal/cleanable/blood/footprints/Crossed(atom/movable/O)
+	..()
 	if(ishuman(O))
 		var/mob/living/carbon/human/H = O
 		var/obj/item/clothing/shoes/S = H.shoes
@@ -136,6 +140,7 @@
 	update_icon()
 
 /obj/effect/decal/cleanable/blood/footprints/Uncrossed(atom/movable/O)
+	..()
 	if(ishuman(O))
 		var/mob/living/carbon/human/H = O
 		var/obj/item/clothing/shoes/S = H.shoes

code/game/objects/effects/decals/cleanable/misc.dm

@@ -101,7 +101,7 @@
 	name = "crusty dried vomit"
 	desc = "You try not to look at the chunks, and fail."
 
-/obj/effect/decal/cleanable/vomit/old/Initialize()
+/obj/effect/decal/cleanable/vomit/old/Initialize(mapload, list/datum/disease/diseases)
 	. = ..()
 	icon_state += "-old"
 

code/game/objects/effects/spawners/gibspawner.dm

@@ -6,7 +6,7 @@
 	var/list/gibamounts = list() //amount to spawn for each gib decal type we'll spawn.
 	var/list/gibdirections = list() //of lists of possible directions to spread each gib decal type towards.
 
-/obj/effect/gibspawner/Initialize(mapload, datum/dna/MobDNA)
+/obj/effect/gibspawner/Initialize(mapload, datum/dna/MobDNA, list/datum/disease/diseases)
 	. = ..()
 
 	if(gibtypes.len != gibamounts.len || gibamounts.len != gibdirections.len)
@@ -24,7 +24,7 @@
 		if(gibamounts[i])
 			for(var/j = 1, j<= gibamounts[i], j++)
 				var/gibType = gibtypes[i]
-				gib = new gibType(loc)
+				gib = new gibType(loc, diseases)
 				if(iscarbon(loc))
 					var/mob/living/carbon/digester = loc
 					digester.stomach_contents += gib