bug#20105: 25.0.50; Emacs manual, `i HOME RET' sends you to `Moving Point', which is wrong

[Drew Adams <drew.adams@oracle.com>]

> Yes, "emacs -Q" here.  And it's not a surprise you have those missing
> candidates in the index, that's how I can see them ;-)
> 
> Are you sure you did 'i home TAB' in the latest manual, though?

Yes, exactly that, in this build:

In GNU Emacs 25.0.50.1 (i686-pc-mingw32)
 of 2015-02-27 on LEG570
Repository revision: b2a590d4e3dc692a97c1b53e015b945d84b4b4c7
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --host=i686-pc-mingw32 --enable-checking=yes,glyphs'

> > > > But why is `HOME' capitalized as a candidate if it points to info
> > > > about the key?
> > >
> > > Don't know.  Looks like some feature of completion.
> >
> > Really?  My guess is instead that it comes from this explicit index
> > entry (which I see in Emacs 24 but not 23): (I removed some whitespace.)
> >
> > * HOME:             Moving Point.        (line  57)
> 
> By "feature" I meant that it replaces "home" which I typed by "HOME",
> for whatever reasons.  The _only_ reason that I could accept as
> legitimate is if _all_ completion candidates started with an
> upper-case "HOME".  But that's not what we have here.  So it looks
> like some attempt at being smart is misfiring.

Yes, I guess so.

But I'm guessing that what happens might have to do with searching the
indexes in order, where Key Index comes first.  And in that index,
`HOME' is the only entry matching input `home'.  It is also the only
matching entry in the Variable Index.

> > That's from the Key Index.  However, note that there are also these
> > two entries in the Variable Index, which seem not to be used when
> > I do `i home TAB':
> >
> > * HOME:             General Variables.   (line  59)
> > * HOSTNAME:         General Variables.   (line  70)
> 
> HOME _is_ used, except that completion removes duplicates (I guess).

I guess so too.  That is a mistake.  The calling function should
decide whether completion should remove duplicates (IMHO).  And in
this case, it should not (IMHO).

> As for HOSTNAME -- why should it be used?  I don't see it used here.

My bad for mentioning HOSTNAME.  Might have been a copy&paste error.
Or it might have reflected a senior moment.

> > From what I see, the only explicit index entries that include `HOME'
> > (capitalized) refer to the home directory, not to the <home> key.
> 
> No, the entry that revers to "Moving Point" is also capitalized.

Right.  Do you agree that that is wrong?  I doubt that that is the
only problem here.  But it would be a start, to fix that entry.
It should be changed to something like `home keyboard key' or `home
key (keyboard)', I think.

(We might also want to add an entry for `<home> keyboard key'.)

Also, I question whether the quote marks should be included in these
two index entries:

* 'HOME' directory on MS-Windows:    Windows HOME.        (line   6)
* 'HOME' directory under MS-DOS:     MS-DOS File Names.   (line  35)

Et voila: That's probably why typing `host' does not match either of
these entries.  And it's perhaps why it does work for you: the curly
quotes are perhaps not present for you, in the indexes.

---

Interestingly, copying and pasting those into this mail shows them
as curly quotes, but in Info they appear to be straight.  They are
LEFT SINGLE QUOTATION MARK etc.  I guess it is the default Info font
that makes them appear straight.

But I thought that we had arranged to use the older makeinfo or
whatever, and that Emacs was arranging to keep simple backtick and
apostrophe in the produced Info buffers.  No?  I see now that Isearch
for ` or ' fails miserably in Info, wrt finding such quoted names.

This makes it hard for users who want to use keyboard keys ` and '
for searching.  That's a clear regression in usefulness, IMHO.