bug#23179: 25.0.92; Restore `M-,' to continue etags search

[Eli Zaretskii]

> From: Andy Moreton <andrewjmoreton@gmail.com>
> Date: Mon, 04 Apr 2016 09:46:38 +0100
> 
> > So you are saying that any new features that present a UI never used
> > before is a bug?
> 
> Of course not. The existing etags based facilities allow search for a
> tag and then subsequent matches without showing any additional windows.
> The new xref based stuff should keep this workflow.

We are miscommunicating.  The new xref stuff is a new feature that
presents a UI never used before.  It cannot keep the tags-based
workflow, because it specifically replaces it with a new one.  And you
said you didn't think such new features are necessarily a bug.  So I
guess we are in violent agreement here.

> >> By all means add new facilites with xref, but without loss of existing
> >> keybindings that many people have ingrained into muscle memory.
> >
> > That's impossible, and you know it.  Not with features that are
> > explicitly meant to replace the old ones.
> 
> Why ever not ?

Because xref wants to replace the old features, not just their
implementation.

> > Anyway, all these opinions should have been brought up many moons ago,
> > when these features were added to the development sources, and perhaps
> > even earlier, when their design and implementation was discussed here.
> > Coming up now, after so much efforts was invested in improving this
> > and documenting it, it's really too late, unless we want to delay the
> > release of Emacs 25.1 by another year or so.  If you don't like some
> > aspects of this feature, the constructive way forward is to submit
> > patches.
> 
> New features are fine, as long as the existing keybindings are retained
> with similar functionality.

Which they are.

> M-, should continue to function as it did for etags

The function M-, invoked for etags is no longer needed with xref.

> Changing long-standing bindings is a disservice to users.

We indeed don't change them too easily, but sometimes we do.  There's
nothing wrong with that, as long as the reasons are good.