bug#57777: 28.2; `vc-dir' picks incorrect backend.

[Mike Woolley]

Steps to repro:

1. Start with a directory having both .Git and CVS sub-directories.
2. Emacs -Q
3. (setq vc-handled-backends '(Git CVS))
4. (vc-dir)
5. Observe `vc-dir’ incorrectly uses the CVS backend rather than Git.
6. Open one of the vc-managed files and the Git backend is (correctly) chosen.
7. This used to work fine in emacs < 28.
8. This issue was masked in 28.1 by bug#54935 forcing me to choose the backend manually.

Thanks,

Mike

In GNU Emacs 28.2 (build 1, aarch64-apple-darwin21.1.0, NS appkit-2113.00 Version 12.0.1 (Build 21A559))

 of 2022-09-12 built on armbob.lan

Windowing system distributor 'Apple', version 10.3.2113

System Description:  macOS 12.6

Configured using:

 'configure --with-ns '--enable-locallisppath=/Library/Application

 Support/Emacs/${version}/site-lisp:/Library/Application

 Support/Emacs/site-lisp' --with-modules'

Configured features:

ACL GMP GNUTLS JSON LIBXML2 MODULES NOTIFY KQUEUE NS PDUMPER THREADS

TOOLKIT_SCROLL_BARS ZLIB

Important settings:

  value of $LANG: en_GB.UTF-8

  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:

  tooltip-mode: t

  global-eldoc-mode: t

  eldoc-mode: t

  show-paren-mode: t

  electric-indent-mode: t

  mouse-wheel-mode: t

  tool-bar-mode: t

  menu-bar-mode: t

  file-name-shadow-mode: t

  global-font-lock-mode: t

  font-lock-mode: t

  blink-cursor-mode: t

  auto-composition-mode: t

  auto-encryption-mode: t

  auto-compression-mode: t

  line-number-mode: t

  indent-tabs-mode: t

  transient-mark-mode: t

Load-path shadows:

None found.

Features:

(cl-print help-fns radix-tree help-mode pp shadow sort mail-extr

emacsbug message rmc puny dired dired-loaddefs rfc822 mml mml-sec epa

derived epg rfc6068 epg-config gnus-util rmail rmail-loaddefs

auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs

password-cache json map text-property-search time-date subr-x mm-decode

mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader

sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils vc-mtn

vc-hg vc-git diff-mode easy-mmode vc-bzr vc-src vc-sccs vc-svn vc-cvs

vc-rcs vc-dir seq byte-opt gv bytecomp byte-compile cconv ewoc vc

cl-loaddefs cl-lib vc-dispatcher iso-transl tooltip eldoc paren electric

uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel

term/ns-win ns-win ucs-normalize mule-util term/common-win tool-bar dnd

fontset image regexp-opt fringe tabulated-list replace newcomment

text-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow

isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax

font-core term/tty-colors frame minibuffer cl-generic cham georgian

utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean

japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european

ethiopic indian cyrillic chinese composite emoji-zwj charscript charprop

case-table epa-hook jka-cmpr-hook help simple abbrev obarray

cl-preloaded nadvice button loaddefs faces cus-face macroexp files

window text-properties overlay sha1 md5 base64 format env code-pages

mule custom widget hashtable-print-readable backquote threads kqueue

cocoa ns multi-tty make-network-process emacs)

Memory information:

((conses 16 71262 11169)

 (symbols 48 8211 8)

 (strings 32 25210 2287)

 (string-bytes 1 793971)

 (vectors 16 17356)

 (vector-slots 8 226555 21748)

 (floats 8 30 67)

 (intervals 56 839 0)

 (buffers 992 17))