From 597a53bbc681089d85b082b46c2e2428dec43b86 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 22 Dec 2021 09:00:52 -0300
Subject: Bug: finalizer calling exit can corrupt finalization order

'os.exit' can call lua_close again, separating new finalizers
created after all previous finalizers were already separated.
---
 testes/main.lua | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'testes')

diff --git a/testes/main.lua b/testes/main.lua
index 52c77954..9def6386 100644
--- a/testes/main.lua
+++ b/testes/main.lua
@@ -261,6 +261,34 @@ u2 = setmetatable({}, {__gc = function () error("ZYX") end})
 RUN('lua -W %s 2> %s', prog, out)
 checkprogout("ZYX)\nXYZ)\n")
 
+-- bug since 5.2: finalizer called when closing a state could
+-- subvert finalization order
+prepfile[[
+-- should be called last
+print("creating 1")
+setmetatable({}, {__gc = function () print(1) end})
+
+print("creating 2")
+setmetatable({}, {__gc = function ()
+  print("2")
+  print("creating 3")
+  -- this finalizer should not be called, as object will be
+  -- created after 'lua_close' has been called
+  setmetatable({}, {__gc = function () print(3) end})
+  print(collectgarbage())    -- cannot call collector here
+  os.exit(0, true)
+end})
+]]
+RUN('lua -W %s > %s', prog, out)
+checkout[[
+creating 1
+creating 2
+2
+creating 3
+nil
+1
+]]
+
 
 -- test many arguments
 prepfile[[print(({...})[30])]]
-- 
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