From 60d897e2298ca1033c79dca8895eaa3a20a63752 Mon Sep 17 00:00:00 2001
From: kikito <kikito@gmail.com>
Date: Mon, 6 Apr 2015 16:54:24 +0200
Subject: [PATCH] attempt to fix lua 5.2

---
 md5.lua | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/md5.lua b/md5.lua
index a68bbc3..bf57972 100644
--- a/md5.lua
+++ b/md5.lua
@@ -39,8 +39,20 @@ local ok, bit = pcall(require, 'bit')
 if not ok then ok, bit = pcall(require, 'bit32') end
 
 if ok then
-  bit_or, bit_and, bit_not, bit_xor = bit.bor, bit.band, bit.bnot, bit.bxor
-  bit_rshift, bit_lshift = bit.rshift, bit.lshift
+
+  bit_not = bit.bnot
+
+  local tobit = function(n)
+    return n <= 0x7fffffff and n or -(bit_not(n) + 1)
+  end
+
+  local normalize = function(f)
+    return function(a,b) return tobit(f(tobit(a), tobit(b))) end
+  end
+
+  bit_or, bit_and, bit_xor = normalize(bit.bor), normalize(bit.band), normalize(bit.bxor)
+  bit_rshift, bit_lshift = normailize(bit.rshift), normalize(bit.lshift)
+
 else
   local function check_int(n)
     -- checking not float