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

[Juri Linkov]

>> The patch is complete and it's working in my tests for ".*" and ".+".
>
> Just ".*" also works for me as it should (as supposed to before, which
> shows that I indeed use your new code).  But if I try "a.*", the
> following matches begin before the file names (my user name ends with
> the letter a).

When Isearch doesn't find "a.*" in the current filename it continues
searching from the beginning of the next Dired line and finds a match
in the details area that contains user names and permissions.
It seems the search should be limited to the end of the filename
on the current line.  But setting the BOUND arg of `search-forward-regexp'
to the end of the filename will cause Isearch to fail for the whole buffer.

BTW, I looked at your previous proof of concept and noticed that even though
it works correctly, its (goto-char (1+ beg)) is very inefficient especially
in the case of ".*" where is advances slowly by 1 character offset
for every search function call in the details area outside of filenames.