Re: master 6b7ff60a5e7: Highlight the suffix in *Completions* buffer in 'basic' style too

[Eshel Yaron]

Hi Juri,

Juri Linkov <juri@linkov.net> writes:

>> Something like the following should fix this issue:
>> [...]
>> @@ -3816,7 +3816,9 @@ completion-basic-all-completions
>>                              'point
>>                              (substring afterpoint 0 (cdr bounds)))))
>>           (all (completion-pcm--all-completions prefix pattern table pred)))
>> -    (completion-pcm--hilit-commonality pattern all)))
>> +    (when all
>> +      (nconc (completion-pcm--hilit-commonality pattern all)
>> +             (car bounds)))))
>
> This fixes file name completion, but at the cost of breaking icomplete-mode:
>
> Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil)
>   >(19 nil)
>   (if (> (length string) pos) (add-face-text-property pos (1+ pos) 
> 'completions-first-difference nil string))
>   (let* ((md (and regexp (string-match regexp string) (cdr (cdr (match-data 
> t))))) ...)
>   completion--hilit-from-re("it-window-to-buffer" "\\`f\\(.*?\\)" 1)
>   completion-lazy-hilit("it-window-to-buffer")
>   icomplete-completions("f" ...)
>   icomplete-exhibit()
>   completing-read-default("M-x " ...)
>   read-extended-command-1("M-x " nil)
>   read-extended-command()
>   command-execute(execute-extended-command)

Hmm that's quite curious...  I can reproduce it also without my change
in 56537ab0228, FWIW.  AFAICT the issue is that icomplete trims the
prefix from completion candidates before passing them to
completion-lazy-hilit, while completion--hilit-from-re expects the full
candidate (prefix included).  I'm not deeply familiar with icomplete,
but maybe calling completion-lazy-hilit before trimming the candidates
as in the diff below should do the trick?

diff --git a/lisp/icomplete.el b/lisp/icomplete.el
index 44bbe9772e4..d03e315fdc8 100644
--- a/lisp/icomplete.el
+++ b/lisp/icomplete.el
@@ -1043,7 +1043,8 @@ icomplete-completions
                   (setq determ (concat open-bracket "" close-bracket)))
                 (while (and comps (not limit))
                   (setq comp
-                        (if prefix-len (substring (car comps) prefix-len) (car 
comps))
+                        (let ((cur (completion-lazy-hilit (car comps))))
+                          (if prefix-len (substring cur prefix-len) cur))
                         comps (cdr comps))
                   (setq prospects-len
                         (+ (string-width comp)
@@ -1052,8 +1053,7 @@ icomplete-completions
                   (if (< prospects-len prospects-max)
                       (push comp prospects)
                     (setq limit t)))
-                (setq prospects
-                      (nreverse (mapcar #'completion-lazy-hilit prospects)))
+                (setq prospects (nreverse prospects))
                 ;; Decorate first of the prospects.
                 (when prospects
                   (let ((first (copy-sequence (pop prospects))))