feature request: mark-modified-lines alternative that marks only when going to an already modified line

[Christoph Anton Mitterer]

Hey.

mark-modified-lines is a pretty nice feature, but it prints the mark
also when one e.g. goes up in the history and then freshly starts
editing the line.

In that situation, one knows obviously that one is editing the history
line and thus working on a modified version.


A nice alternative could be the following:
One goes up to some history element, modifies it (the first time, so no
mark is printed), one goes e.g. further up and then again down to the
already modified line.... and *now* (because on reaches a line that has
been modified, but not just now), the mark is printed.

I think this would work nicely with both revert-all-at-newline On or
Off.


Thanks,
Chris.


PS: "feature request" is obviously meant in the sense of
suggestion/idea.