lua_gc not documented as possibly raising errors

[Edoardo Lolletti]

Currently the reference manual lists lua_gc as not raising any error,
but it can indeed raise them as it can end up calling a __gc metamethod,
thus running arbitary lua code and possibly raising errors.

[Sainan]

No, errors raised in __gc metamethods are special in that such errors are demoted to warnings, e.g.:

setmetatable({}, {
__gc = function() error("oops") end
})

will exit successfully, and if you enable warnings, it'll print:

warning: error in __gc (index.pluto:2: oops)

-- Sainan

[Edoardo Lolletti]

I see, I had forgotten about that detail, thanks