Subject: bug#29833: icomplete re-build the completion table after each key press

From: Shuguang Sun <[email-masked]>
Date: Sun, 24 Dec 2017 16:58:28 +0800

Hi,

The icomplete re-build the completion table
'completion-all-sorted-completions' after each key press. However, I think
it should keep the 'completion-all-sorted-completions' builded at beging
and re-use it afterwise.

At least in Windows, GNU Emacs 27.0.50 (build 1, x86_64-w64-mingw32) of
2017-12-09.

How to repeat it:
1: emacs -q
2: icomplete-mode (we can't find anything wired unless we call
dired-do-copy on a network-mapped remote file under a slow network)
3: modify function icomplete-exhibit to log as below:
    insert '(print completion-all-sorted-completions)' between
'(save-excursion  (goto-char (point-max))' and '(if (and (or
icomplete-show-matches-on-no-input', and C-M-x.
    Then it will print 'nil' after each key press which means
'completion-all-sorted-completions' is empty.
4. modify function icomplete-completions to log as below:
    insert '(print completion-all-sorted-completions)' at the begining of
the function body, prior to "(let* ((minibuffer-completion-table
candidates)'.
    Then it will print 'nil' after each key press which means
'completion-all-sorted-completions' is empty.

Thereby, it has to call "(comps (completion-all-sorted-completions
(icomplete--field-beg) (icomplete--field-end)))' in function
icomplete-completions to re-build the completiong table after each key
press.

Thanks *Stefan Monnier *to point out it should be a bug in the help
maillist.

By the way, '(sequencep (icomplete--completion-table))' in function
icomplete-exhibit always returns 'nil', and the
icomplete-delay-completions-threshold actually has no effect.
(print (icomplete--completion-table)) just returns the table name (function
to generate the table), but not the content of the table.

By the way again, if call dired-do-copy or dired-do-rename,
icomplete-max-delay-chars counts the whole path of the file because, the
path has been put to the minibuffer automatically. This may not a bug,
however, I think it should be documented.

Best Regards,
Shuguang Sun