In pursuing a 'best' solution for bug-report#43412, I've taken the
plunge and gotten an emacs 28 snapshot installed locally, and in
examining the code, saw things that didn't make sense to me or were
unnecessary or could just do with better readability. My testing
indicates no harm done by the changes, but they should be peer-reviewed
and undergo further testing. Nothing in the attached patch is aimed at
changing functionality, so you may want to reject it on the basis of "if
it ain't broke, don't fix it", but it does improve the code.

Just as a 'for example': I started on this because I saw that the code
was saving match data, which had me on a wild goose chase hunting for
why and where it was necessary - I found nothing, and removing the code
doesn't seem to have ill effect.

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