From 4205efb6d084a2ef2cc2fff74e744550e13e4665 Mon Sep 17 00:00:00 2001
From: Jude Melton-Houghton <jwmhjwmh@gmail.com>
Date: Thu, 29 Jul 2021 10:11:43 -0400
Subject: [PATCH] Handle getting out-of-bounds bits in get_bit

The binary state is not padded with zeroes, so they must be inferred.
---
 mesecons/util.lua | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/mesecons/util.lua b/mesecons/util.lua
index 3cdeb64..846c995 100644
--- a/mesecons/util.lua
+++ b/mesecons/util.lua
@@ -163,8 +163,13 @@ function mesecon.getbinstate(nodename, states)
 end
 
 function mesecon.get_bit(binary,bit)
-	bit = bit or 1
-	local c = binary:len()-(bit-1)
+	local len = binary:len()
+	if bit then
+		if bit > len then return false end
+	else
+		bit = 1
+	end
+	local c = len-(bit-1)
 	return binary:sub(c,c) == "1"
 end