[luatex] Luatex: \toksapp seems to be not local

[Petr Olsak]

Hello,

I started to using LuaTeX with my macros (OpTeX) and I reached first 
problem.

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\toks0={A}

{\toksapp0{B}\the\toks0 }

\the\toks0

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This is LuaTeX, Version 1.12.0 (TeX Live 2020)

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I expected that first printing of \toks0 gives AB and the second only A. 
But it is not true. The second printing is AB too.

It seems that \toksapp (and variants) makes global assignment. The 
manual of LuaTeX does not mention explicitly that the assignment is 
local, but the \g* variants are here and they are global. So, I derived, 
that non-\g* variants are local. But it is not true.

Petr Olšák