Re: something like linum.el ought to be added

[Markus Triska <markus.triska@gmx.at>]

martin rudalics <rudalics@gmx.at> writes:

> Then you'd have to update line numbers in `after-make-frame-functions'

Yes, that would also be an option; the current way subsumes more
specialized cases like this with little overhead.

> An aside: Sometimes configuration, buffer text, and some window start
> position change within one and the same command.  Did you check whether
> this cause line number updating run two, three times after the command?

No; generally, I found updates to be so fast that this, even if it
should occur, is not a concern. Also, when line numbers for a window
are updated twice in a row, all overlays are already created and in
the right place, so it is even less noticable than starting anew.