Does the following formulation of your question accurately convey what you ask?
~~~
function global_function()
-- ...
end
local function upvalue_function()
-- ...
end
function f1(param_function)
_ENV = {NAME='f1_env'; global_function = global_function}
global_function() -- Can this call change _ENV.NAME? Or even _ENV itself?
upvalue_function() -- Can this call change _ENV.NAME? Or even _ENV itself?
param_function() -- Can this call change _ENV.NAME? Or even _ENV itself?
end
~
Yes. Within any of global/upvalue/param_function, can they change f1's _ENV contents or f1's _ENV itself? Consider also the case (actually the primary case for what I'm considering) where f1 is not a normal function, but the anonymous function of a compiled chunk, such as a module being loaded by require().
