bug#14013: 24.3.50; dired-isearch-filenames-regexp is matching text outside filenames

[Juri Linkov]

> Thanks.  I quickly tested your patch, and it seems to work well so far

Thanks for testing, this confirms that the proof of concept is viable,
so now the docstrings could be updated as well.

> (except for the ^ thing fo course).  Also highlighting worked.

To implement ^, I see no way other than special handling:
when a regexp begins with ^, then after removing ^ from the regexp,
call 'looking-at' at the beginning of the file name.

> Anything particular I should keep my eye on?

Please help to decide how search/replace should be implemented in WDired.
The current implementation filters out read-only parts of the Dired buffer.
Should the new search function also skip read-only parts or should it
match only on file names in WDired the same way as in Dired?

>>  (defun wdired-change-to-wdired-mode ()
>> @@ -238,8 +239,9 @@ wdired-change-to-wdired-mode
>>    (setq-local wdired--old-point (point))
>>    (wdired--set-permission-bounds)
>>    (setq-local query-replace-skip-read-only t)
>> -  (add-function :after-while (local 'isearch-filter-predicate)
>> -                #'wdired-isearch-filter-read-only)
>> +  (add-function :around (local 'isearch-search-fun-function)
>> +                #'dired-isearch-search-filenames)
>> +  (setq-local replace-re-search-function #'dired-isearch-search-filenames)
>
> And: Is it intended that this is unconditional (I would expect a
> `dired-isearch-filenames-mode' test)?

Currently it is unconditional when it's using isearch-filter-predicate.
So maybe it should be kept this way since it's what was used for many years?
Or is there a reason to change the current behavior?