Merge pull request #15393 from LanCartwright/needsallcures

Adds var/needs_all_cures

code/datums/diseases/_disease.dm

@@ -61,7 +61,7 @@ var/list/diseases = subtypesof(/datum/disease)
 	var/permeability_mod = 1
 	var/severity =	NONTHREAT
 	var/list/required_organs = list()
-
+	var/needs_all_cures = TRUE
 	var/list/strain_data = list() //dna_spread special bullshit
 
 
@@ -90,12 +90,12 @@ var/list/diseases = subtypesof(/datum/disease)
 	if(!(disease_flags & CURABLE))
 		return 0
 
-	. = 1
+	. = cures.len
 	for(var/C_id in cures)
 		if(!affected_mob.reagents.has_reagent(C_id))
 			.--
-			break //One missing cure is enough to fail
-
+	if(!. || (needs_all_cures && . < cures.len))
+		return 0
 
 /datum/disease/proc/spread(atom/source, force_spread = 0)
 	if((spread_flags & SPECIAL || spread_flags & NON_CONTAGIOUS || spread_flags & BLOOD) && !force_spread)