bug#49143: 28.0.50; find-file-literally doesn't ignore `mode:`

[Stefan Monnier]

Package: Emacs
Version: 28.0.50


Contrary to its documentation, it seems that `find-file-literally`
doesn't ignore file-local `mode:` settings any more, as evidenced by the
following backtrace:

    dismal-mode()
    hack-one-local-variable(mode dismal)
    hack-local-variables-apply()
    hack-local-variables(no-mode)
    run-mode-hooks()
    fundamental-mode()
    set-buffer-major-mode(#<buffer normalization.dis>)
    set-auto-mode()
    normal-mode(t)
    after-find-file(nil t)
    find-file-noselect-1(#<buffer normalization.dis> "~/tmp/normalization.dis" 
nil nil "~/tmp/normalization.dis" (1347023 65026))
    find-file-noselect("~/tmp/normalization.dis")

I suspect the culprit is

    commit 5bedbe6b1d5f4b801abf91b4d023d5c4e66418f0
    Author: Lars Ingebrigtsen <larsi@gnus.org>
    Date:   Mon May 10 12:40:11 2021 +0200
    
        Always heed the `lexical-binding' local variable
        
        * doc/lispref/variables.texi (File Local Variables): Document
        `permanently-enabled-local-variables'.
        
        * lisp/files.el (enable-local-variables): Mention the new variable.
        (set-auto-mode): Always call `hack-local-variables'.
        (hack-local-variables): Factor out the variable gathering into its
        own function, and respect the new variable (bug#47843).
        (hack-local-variables--find-variables): Factored out from
        `hack-local-variables'.
        (permanently-enabled-local-variables): New variable.


-- Stefan