bug#39902: 28.0.50; Marking in dired with active region

[Juri Linkov]

> What I expect is a behavior analogue to "graphical" file browsers (with
> icons and such - I don't use one, but anyway).  When you mark a region
> there with the mouse, all files "touched" are in.  And it's enough when
> the icon is included, i.e. the file is not identified with the
> occurrence of the name on the screen but with the whole representation,
> including the icon etc.  I guess that's where my way of thinking comes
> from.

I tried in the default graphical file browser that I have available,
its name is Caja - the file manager for the MATE desktop,
and it works exactly like Emacs currently works:
it doesn't select files based on lines, but it selects only files
whose filenames are inside the selection.  Here is the screenshot:

But OTOH, it doesn't have the exact analogy with Emacs,
and I know no other files manager exactly like Dired.

> If expectations might be that different maybe the behavior should be
> made controllable with a new user option?

A new user option will help in any case.  But before adding it, maybe we
could try to improve the visual feedback of selection in Dired.  Would it
be possible to display the whole line (including file name) highlighted
with the 'region' face, even when point is still before the file name?

If this is not possbile to implement, then a new user option could have
a name 'dired-mark-non-selected-files' or 'dired-mark-files-on-current-line'.