More effort in avoiding errors in finalizersHEADmaster

Before calling a finalizer, Lua not only checks stack limits, but
actually ensures that a minimum number of slots are already allocated
for the call. (If it cannot ensure that, it postpones the finalizer.)
That avoids finalizers not running due to memory errors that the
programmer cannot control.

1 files changed, 19 insertions, 0 deletions

diff --git a/testes/memerr.lua b/testes/memerr.lua
index 9c940ca7..a55514a9 100644
--- a/testes/memerr.lua
+++ b/testes/memerr.lua
@@ -282,6 +282,25 @@ testamem("growing stack", function ()
   return foo(100)
 end)
 
+
+collectgarbage()
+collectgarbage()
+global io, T, setmetatable, collectgarbage, print
+
+local Count = 0
+testamem("finalizers", function ()
+  local X = false
+  local obj = setmetatable({}, {__gc = function ()  X = true end})
+  obj = nil
+  T.resetCI()   -- remove extra CallInfos
+  T.reallocstack(18)   -- remove extra stack slots
+  Count = Count + 1
+  io.stderr:write(Count, "\n")
+  T.trick(io)
+  collectgarbage()
+  return X
+end)
+
 -- }==================================================================