bug#37496: 27.0.50; C-s failing to search

[Jean Louis <bugs@gnu.support>]

Dear Juri,

Thank you much for M-x isearch-diagnostics function. I am keeping it
ready for case that I get into problem again. I was editing 600
directories and many PDF file names inside, and there is yet left to
be edited, so I hope to encounter the same problem again.

I would not patch that now as I cannot reproduce the bug
intentionally, I can just hope it will happen again and would let you
all know.

Jean

* Juri Linkov <juri@linkov.net> [2019-10-07 21:01]:
> Next time you encounter this problem please try running this diagnostics
> with just 'M-x isearch-diagnostics RET' in the buffer where isearch fails:
> 
> (defun isearch-diagnostics ()
>   (interactive)
>   (let* ((variables
>           '(major-mode
>             buffer-read-only
>             isearch-mode
>             isearch-success
>             isearch-error
>             isearch-wrapped
>             isearch-adjusted
>             isearch-suspended
>             isearch-regexp
>             isearch-case-fold-search
>             isearch-invisible
>             isearch-hidden
>             isearch-allow-scroll
>             isearch-search-fun-function
>             isearch-wrap-function
>             isearch-push-state-function
>             isearch-mode-hook
>             isearch-update-post-hook
>             isearch-mode-end-hook
>             isearch-filter-predicate
>             dired-isearch-filenames
>             dired-isearch-filenames-mode))
>          (diagnostics
>           (concat
>            (mapconcat
>             (lambda (v)
>               (format "%s: %s %s" v
>                       (cl-prin1-to-string (and (boundp v) (buffer-local-value v (current-buffer))))
>                       (cl-prin1-to-string (and (boundp v) (default-value v)))))
>             variables "\n")
>            (format "\nany read-only: %S\n" (text-property-any (point-min) (point-max) 'read-only t)))))
>     (display-buffer
>      (with-current-buffer (get-buffer-create "*isearch-diagnostics*")
>        (erase-buffer)
>        (insert diagnostics)
>        (current-buffer)))))
> 
> From what I see wdired doesn't restore a previous value of isearch-filter-predicate.
> This is fine as long as there are no read-only properties kept in the
> Dired buffer, but it seems in your case read-only properties might be
> still present after finishing Wdired-mode.  If you can reproduce the bug
> please also try the following patch that could fix it:
> 
> diff --git a/lisp/wdired.el b/lisp/wdired.el
> index 44f083bb7f..35f1b5ebbd 100644
> --- a/lisp/wdired.el
> +++ b/lisp/wdired.el
> @@ -357,6 +357,8 @@ wdired-change-to-dired-mode
>      (remove-text-properties
>       (point-min) (point-max)
>       '(front-sticky nil rear-nonsticky nil read-only nil keymap nil)))
> +  (remove-function (local 'isearch-filter-predicate)
> +                   #'wdired-isearch-filter-read-only)
>    (use-local-map dired-mode-map)
>    (force-mode-line-update)
>    (setq buffer-read-only t)
>