bug#38457: 27.0.50; dabbrev-expand regression due to message change

[Dmitry Gutov]

On 25.12.2019 1:47, Juri Linkov wrote:
> > > IDK, I tried to set resize-mini-windows to nil and in icomplete-mode
> > > can see the message.
> >
> > My bad, last time I was trying it was with ido-mode. There, the message
> > comes at the end of all completions.
> >
> > With icomplete, however, it's printed before the completions. And it also
> > appears to the left of the cursor. Is that intentional?
>
> Code in set-minibuffer-message was copied from minibuffer-message
> where handling of the cursor and after-string overlay was intentional.

Since after-string is used, shouldn't it always appear *after* the cursor?

> Could ido-mode use an overlay the same way as it's used in icomplete
> that plays nicely with the set-minibuffer-message overlay?

This seems to work, but it needs more testing:

diff --git a/lisp/ido.el b/lisp/ido.el
index 79f259b819..d47450fc40 100644
--- a/lisp/ido.el
+++ b/lisp/ido.el
@@ -4492,6 +4492,8 @@ ido-initiate-auto-merge
        (ido-tidy))
       (throw 'ido contents))))

+(defvar ido--overlay nil)
+
 (defun ido-exhibit ()
   "Post command hook for Ido."
   ;; Find matching files and display a list in the minibuffer.
@@ -4726,7 +4728,12 @@ ido-exhibit
        (let ((inf (ido-completions contents)))
          (setq ido-show-confirm-message nil)
          (ido-trace "inf" inf)
-         (insert inf))
+          (when ido--overlay
+            (delete-overlay ido--overlay))
+          (let ((o (make-overlay (point-max) (point-max) nil t t)))
+            (when (> (length inf) 0)
+              (put-text-property 0 1 'cursor t inf))
+            (overlay-put o 'after-string inf)
+            (setq ido--overlay o)))
        ))))

 (defun ido-completions (name)