# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1619196811 -3600
# Node ID 0584f8251f88811fe2d7e8b25f1ec6cbb6ee34b7
# Parent  04cfdac393cca274d78ff46d40aee7723907d696
tests: Add test for correct GC with circular references

This tests for an issue fixed by a8caec6c5429, where a callback holding a
reference to the parser object was never collected. This was due to use of
luaL_ref() which forced a reference to the callbacks table even when the
parser was otherwise not referenced.

diff -r 04cfdac393cc -r 0584f8251f88 tests/test.lua
--- a/tests/test.lua	Fri Apr 23 17:50:29 2021 +0100
+++ b/tests/test.lua	Fri Apr 23 17:53:31 2021 +0100
@@ -357,6 +357,18 @@
 collectgarbage(); collectgarbage()
 assert(math.abs(gcinfo() - x) <= 2)
 
+-- test for GC (circular references)
+print("testing garbage collection (circular reference)")
+collectgarbage(); collectgarbage()
+local x = gcinfo()
+for i=1,100000 do
+  -- due to a small bug in Lua...
+  if (math.mod or math.fmod)(i, 100) == 0 then collectgarbage() end
+  local p;
+  p = lxp.new({ StartElement = function () print(p) end });
+end
+collectgarbage(); collectgarbage()
+assert(math.abs(gcinfo() - x) <= 2)
 
 print"OK"