bug#53876: 27.2; "eval: (X-mode)" is always safe as file local variable

[Glenn Morris]

I suppose the assumption is that code already available in the user's
environment is not intrinsically malicious (ie does not contain
deliberately harmful mode definitions). Rather the file-local variables
safety mechanisms are intended to protect against malicious code
actually embedded in the file being visited; something like eval:
(shell-command ...).

It underlines again the need to be careful about what elisp libraries
one installs (although the simple act of installing a package can
already directly execute arbitrary code anyway).