Re: [BUG] org-insert-link should use DEFAULT in read-string when asking for description

[Max Nikulin]

On 27/02/2022 23:16, Visuwesh wrote:
> [ஞாயிறு, பிப்ரவரி 27 2022] Max Nikulin wrote:
> > On 26/02/2022 21:16, Visuwesh wrote:
> > > [சனி, பிப்ரவரி 26 2022] Max Nikulin wrote:
> > >
> > > > Are you suggesting replacing
> > > >       (read-string "rs-initial: " "Some initial")
> > > > by
> > > >       (read-string "rs-default: " nil nil "Some default")
> > > > ?
> > > Yes, exactly.
> >
> > However you agreed that it would be regression since empty description
> > use case would be impossible.
>
> No.  It is impossible to do it using read-string, but it is possible to
> do it by writing a function that calls read-from-minibuffer (and I gave
> an example of a function that does this).
>
> > > I admit that I forgot about this but Emacs can be made to not translate
> > > empty string to the default argument if you DTRT when calling
> > > `read-from-minibuffer' (and `read-shell-command' does this).  If writing
> > > a new function just to get this functionality is too much, then I guess
>      2. The reason why I cited read-shell-command does not have anything
>         to do with the usefulness of empty string (or shell command).  I
>         merely wanted to point out that you can have BOTH the DEFAULT
>         argument (and no INITIAL), and can make the empty string a valid
>         output from the function (i.e., without getting substituted by
>         the DEFAULT argument).

In my opinion deprecation of the INITIAL argument without some descent 
replacement was a mistake. I suspect that such statement appeared 
without realizing of the problem with discriminating default vs. empty 
value. `read-string' oversimplify it by assumption that users do not 
need empty values at all. Your first argument was that INITIAL is 
deprecated but in the next message you pointed to a function that still 
uses the INITIAL argument. On the other hand `read-shell-command' 
belongs to command for which empty return value is hardly meaningful 
despite it is possible. That is why I disputed that `read-shell-command' 
is a good example of `read-from-minibuffer' usage in the context of 
`org-insert-link'.

> Please read the docstring of read-from-minibuffer.  You would be better
> served by reading it than me replicating it here.  And I gave
> read-shell-command as an example so others could study the function.
>
> In essence, you can get the old behaviour (1) but you need to type M-n
> beforehand.  Its one more key but it is far better than the current
> behaviour since it is consistent with rest of the Emacs ecosystem (see
> below also).

I do not think it is a good idea to require extra M-n to keep the 
*current* description when a user hit C-c C-l to edit the link target 
with no intention to touch its description.

> With every command I use, when I know that the DEFAULT argument will be
> of no use, I simply start typing.  However, with org-insert-link I have
> to clear the input _first_ then start typing.  This never happens
> elsewhere, even in grep (which you cite as an example)!

I agree that it is great to be able to just start typing to replace 
default description. Unfortunately similar to significant fraction of 
interfaces, `org-insert-link' behavior is a result of trade-offs and 
compromises. If you see a way to improve it, please, submit a patch or 
at least post a code that can be tried from a src block or from the 
*scratch* buffer to evaluate possible regressions and unaddressed use cases.