bug#65348: INITIAL-INPUT in completing-read repeats same entry twice consecutively

[Drew Adams]

> > > The introduction of HIST is only making a good
> > > function quite terrible to use, becoming an
> > > over-engineering piece of junk to avoid.
> >
> > Useless to claim, without saying why you think so.
> > And you're quite wrong here, FWIW. HIST is your
> > friend.
> 
> When using my own function that selects from a collection, I am never
> interested in the history.  Just want it to cycle through the entries,
> that's all.  And the less things I got to type, the better.

Everyone is different.

But know that cycling is not always an efficient
way to get to something.  It can be fine if the
thing you want to get to is close by.  It can be
_awful_ if it's far.

This is why we have keys such as `M-r' and `M-s'
that find things in the history.

It can also help to have completion against the
history.  (If you'd read the page I pointed to
about Icicles history enhancements you'd have
seen more than one possibility for that.)

Cycling can be helpful for accessing COLLECTION
matches or for accessing history elements.  But
cycling is an inherently dumb, inefficient way
to find a needle in a haystack.  A magnet works
better than checking each bit of hay in turn.

Being able to sort completion candidates is one
way to tame dumb cycling.  Being able to filter
them is another.  It's really important to have
ways to tame a large set of choices, whether
they are completion candidates, input-history
candidates, or anything else.

> > Callers of `completing-read' can decide whether it
> > makes sense (they think) to insert. And users
> > should be able to override the caller's choice.
> 
> It seems that now I have to know all about the HIST things,
> the DEF, the over-riding of same value to call some function
> that I have to write to get the behaviour I was using, etc.

You don't have to know anything.  And yes, there
are a multitude of things you can learn, to make
your Emacs life easier, more efficient, more
enjoyable, more enlightening.

Some people use Emacs for a long time without
bothering to learn other ways of doing things
than what they learned the first week.  Some use
menus and mouse alone, pretty much.  Others get
along better as time goes on, picking up various
ways to do things easier or quicker.  Often that
includes writing some code or picking up some
code (e.g. packages) written by others.  YMMV.