Is CVE-2019-6706 in Lua 5.4 fixed?

[jakub.kulik@...]

Hi

I was recently investigating the state of CVE-2019-6706, and it seems 
that while this was fixed in 5.3 branch [1], it was not forward-ported 
to 5.4. Is that the case or am I missing some other change that makes 
this nonissue?

Best Regards,
Jakub

[1] 
https://github.com/lua/lua/commit/89aee84cbc9224f638f3b7951b306d2ee8ecb71e

[CVE-2019-6706 discussion] 
http://lua.2524044.n2.nabble.com/Bug-Report-Use-after-free-in-debug-upvaluejoin-tc7685506.html