Fixes "????" making you vomit more than normal (#24230)

* Dummy disease check

* Contra review

* Update code/datums/diseases/advance/advance.dm

Co-authored-by: Contrabang <91113370+Contrabang@users.noreply.github.com>

---------

Co-authored-by: Contrabang <91113370+Contrabang@users.noreply.github.com>

code/datums/diseases/_MobProcs.dm

@@ -2,9 +2,9 @@
 /mob/proc/HasDisease(datum/disease/D)
 	for(var/thing in viruses)
 		var/datum/disease/DD = thing
-		if(D.IsSame(DD))
-			return 1
-	return 0
+		if(DD.IsSame(D))
+			return TRUE
+	return FALSE
 
 
 /mob/proc/CanContractDisease(datum/disease/D)

code/datums/diseases/_disease.dm

@@ -158,10 +158,9 @@ GLOBAL_LIST_INIT(diseases, subtypesof(/datum/disease))
 	qdel(src)
 
 /datum/disease/proc/IsSame(datum/disease/D)
-	if(istype(src, D.type))
-		return 1
-	return 0
-
+	if(ispath(D))
+		return istype(src, D)
+	return istype(src, D.type)
 
 /datum/disease/proc/Copy()
 	var/datum/disease/D = new type()

code/datums/diseases/advance/advance.dm

@@ -86,13 +86,16 @@ GLOBAL_LIST_INIT(advance_cures, list(
 
 // Compares type then ID.
 /datum/disease/advance/IsSame(datum/disease/advance/D)
+	if(ispath(D))
+		return FALSE
 
-	if(!(istype(D, /datum/disease/advance)))
-		return 0
+	if(!istype(D, /datum/disease/advance))
+		return FALSE
 
 	if(GetDiseaseID() != D.GetDiseaseID())
-		return 0
-	return 1
+		return FALSE
+
+	return TRUE
 
 // To add special resistances.
 /datum/disease/advance/cure(resistance=1)