Re: find-file-noselect needs save-match-data

[Richard Stallman]

    99% of non-trivial functions use regexps.  So you cannot assume a function
    doesn't use regexps just because it doesn't say that it uses regexps.
    It's rather the opposite: a function can only be assumed not to use regexps
    if it is really trivial/primitive (e.g. `car' or `expand-file-name').

I almost agree with you.  There are some functions that aren't
literally primitive, but seem like things that should be safe to call.
file-truename is an example.  It would be good to make file-truename
safe regarding regexps.

find-file-noselect doesn't have to be regexp-safe, but why not make it
regexp-safe, since it is so slow.

However, we shouldn't go around trying to make all Emacs functions
regexp-safe.