bug#20195: 25.0.50; Let Dired commands such as `dired-do-search' (`A') use prefix arg

[Drew Adams <drew.adams@oracle.com>]

Enhancement request:

Typically in Dired commands that act on the marked files will act on the
next PREFIX-ARG files instead, if a prefix arg is provided.  This is not
true of commands such as `dired-do-search', but it would be good if it
were.

All that is needed is to (a) add an optional argument ARG to each such
command and (b) include ARG in the call to `dired-get-marked-files'.
For example:

(defun dired-do-search (regexp &optional arg) ; <=== Add ARG
  "..."
  (interactive "sSearch marked files (regexp): \nP")
  (tags-search
    regexp (dired-get-marked-files nil arg 'dired-nondirectory-p)))
                                        ^
                                        |
                                     use ARG


In GNU Emacs 25.0.50.1 (i686-pc-mingw32)
 of 2014-10-20 on LEG570
Bzr revision: 118168 rgm@gnu.org-20141020195941-icp42t8ttcnud09g
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking=yes,glyphs CPPFLAGS=-DGLYPH_DEBUG=1'