bug#32536: displayed width of man pages

[Juri Linkov <juri@linkov.net>]

> Perhaps if they /can/ be reformatted dynamically, have a variable like
> `Man-dynamic-reformat-lines-max' so users can prevent the reformatting
> for instances in which it takes too long.  Then a problem is that the
> number of lines varies with the width of the page, and instead of the
> number of lines, the size in bytes (kB, MB ...) of the page might be
> more relevant for reformatting it.
>
> Unfortunately, users usually have no idea what the size of a manual page
> in bytes is, and the pages are even stored compressed.  Users would have
> to try out what size makes sense to dynamically reformat on their
> particular hardware and may end up simply turning the feature off
> because they do not resize windows while reading manual pages anyway.
>
> Does it take longer to format the same manual page into 2500 lines or
> into 5000 lines?
>
> Would it be possible to do the reformatting in the background, and
> delayed, like fontifying a buffer?

Man pages are already formatted asynchronously in the background,
so actually reformatting on window resize should be quite responsible
even for large manuals (maybe an addition flag is needed to prevent
updating when a previous update is in progress).

You can try and see how fast it reformats, typing repeatedly the key `u'
(Man-update-manpage).