Fixes

code/modules/atmospherics/gasmixtures/gas_mixture.dm

@@ -172,9 +172,12 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 	
 /datum/gas_mixture/react(datum/holder)
 	. = NO_REACTION
+	if(!total_moles())
+		return
 	var/list/reactions = list()
-	for(var/I in get_gases())
-		reactions += SSair.gas_reactions[I]
+	for(var/datum/gas_reaction/G in SSair.gas_reactions)
+		if(get_moles(G.major_gas))
+			reactions += G
 	if(!length(reactions))
 		return
 	reaction_results = new
@@ -195,9 +198,22 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 					continue
 				if(get_moles(id) < min_reqs[id])
 					continue reaction_loop
+			//at this point, all minimum requirements for the reaction are satisfied.
 
+			/*	currently no reactions have maximum requirements, so we can leave the checks commented out for a slight performance boost
+				PLEASE DO NOT REMOVE THIS CODE. the commenting is here only for a performance increase.
+				enabling these checks should be as easy as possible and the fact that they are disabled should be as clear as possible
+			var/list/max_reqs = reaction.max_requirements
+			if((max_reqs["TEMP"] && temp > max_reqs["TEMP"]) \
+			|| (max_reqs["ENER"] && ener > max_reqs["ENER"]))
+				continue
+			for(var/id in max_reqs)
+				if(id == "TEMP" || id == "ENER")
+					continue
+				if(cached_gases[id] && cached_gases[id][MOLES] > max_reqs[id])
+					continue reaction_loop
 			//at this point, all requirements for the reaction are satisfied. we can now react()
-
+			*/
 			. |= reaction.react(src, holder)
 			if (. & STOP_REACTIONS)
 				break