From 1e19ea02908b5d302322bb83ebd4c8e20aa155de Mon Sep 17 00:00:00 2001
From: Lorenzo Cogotti <lcg@doublefourteen.io>
Date: Sun, 2 Oct 2022 15:58:50 +0200
Subject: [PATCH] [crush] Add Lua version compatibility check.

---
 crush.lua | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/crush.lua b/crush.lua
index 5777248..d7d4cd2 100644
--- a/crush.lua
+++ b/crush.lua
@@ -7,6 +7,33 @@
 local io = require 'io'
 local os = require 'os'
 
+-- Lua version check
+
+local function check_version()
+    -- Generic Lua version check - 5.2 required
+    if _VERSION then
+        local maj, min = _VERSION:match("Lua (%d+)%.(%d+)")
+
+        if maj and min then
+            maj, min = tonumber(maj), tonumber(min)
+            if maj > 5 or (maj == 5 and min >= 2) then
+                return true
+            end
+        end
+    end
+
+    -- LuaJIT check - 2.0.0 required (technically 2.0.0_beta11)
+    if jit and jit.version_num and jit.version_num >= 20000 then
+        return true
+    end
+
+    return false
+end
+
+if not check_version() then
+    error("Unsupported Lua version!\nSorry, crush requires Lua 5.2 or LuaJIT 2.0.0.")
+end
+
 -- System specific functions
 --
 -- Portions of this code are based on work from the LuaRocks project.