From cc493e08eec57a1311314af6b08d6d97db5d3f77 Mon Sep 17 00:00:00 2001
From: SECBATON GRIFFON <87321915+SECBATON-GRIFFON@users.noreply.github.com>
Date: Tue, 25 Jun 2024 15:56:58 +0100
Subject: [PATCH] Fixes possible molar ratio runtime (#36695)

---
 code/ZAS/_gas_mixture.dm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/ZAS/_gas_mixture.dm b/code/ZAS/_gas_mixture.dm
index 4bfae0621e0..2b55707eb91 100644
--- a/code/ZAS/_gas_mixture.dm
+++ b/code/ZAS/_gas_mixture.dm
@@ -132,7 +132,7 @@
 	return temperature * heat_capacity()
 
 /datum/gas_mixture/proc/molar_ratio(g) //ratio of moles of the input gas to total mols of all gasses in the area
-	return src[g] / total_moles
+	return total_moles && (src[g] / total_moles) //&& short circuits if total_moles is 0, and returns the second expression if it is not.
 
 /datum/gas_mixture/proc/molar_density(g) //Per liter. You should probably be using pressure instead, but considering this had to be made, you wouldn't be the first not to.
 	return (g ? src[g] : total_moles) / volume