From 0c9a37cb423aebae46cf3de3233a83d04648c5dd Mon Sep 17 00:00:00 2001
From: Jude Melton-Houghton <jwmhjwmh@gmail.com>
Date: Fri, 11 Feb 2022 11:46:28 -0500
Subject: [PATCH] Add explanatory comment

---
 mesecons/util.lua | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mesecons/util.lua b/mesecons/util.lua
index 55a0d63..ceabfdf 100644
--- a/mesecons/util.lua
+++ b/mesecons/util.lua
@@ -395,7 +395,10 @@ end
 --
 -- The swap will necessitate a light update unless update_light equals false.
 function mesecon.vm_swap_node(pos, name, update_light)
+	-- If one node needs a light update, all VMs should use light updates to
+	-- prevent newly calculated light from being overwritten by other VMs.
 	vm_update_light = vm_update_light or update_light ~= false
+
 	local tbl = vm_get_or_create_entry(pos)
 	local index = tbl.va:indexp(pos)
 	tbl.data[index] = minetest.get_content_id(name)