bug#81613: [PATCH] Make vc-dir use display-buffer instead of pop-to-buffer

From f358bb37b3bebd2f63cbb4cd30b735d16ffa79e1 Mon Sep 17 00:00:00 2001
Message-ID: <f358bb37b3bebd2f63cbb4cd30b735d16ffa79e1.1786705662.git.info@protesilaos.com>
From: Protesilaos <[email protected]>
Date: Fri, 14 Aug 2026 14:07:32 +0300
Subject: [PATCH] Make vc-dir set its major mode before displaying its buffer

* etc/NEWS: Announce the change.
* lisp/vc/vc-dir.el (vc-dir): Create the buffer, prepare it, then call 'pop-to-buffer'.
---
 etc/NEWS          |  6 ++++++
 lisp/vc/vc-dir.el | 26 ++++++++++++++------------
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 43c667647e1..f7791658896 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -197,6 +197,12 @@ has a VC backend.  If it doesn't, but the directory's truename does
 have a backend, and 'vc-follow-symlinks' is non-nil, the truename is
 used instead.  Previously, the truename was used unconditionally.
 
+---
+*** VC-Dir sets its major mode before displaying its buffer.
+This means that a 'display-buffer-alist' element can now match the
+buffer with '(derived-mode . vc-dir-mode)'. Whereas before it could only
+match it reliably with a regular expression like "\\`\\*vc-dir\\*\\'".
+
 +++
 *** Improved creation of commit log entry from ChangeLog.
 When VC detects that all log entries for the current changeset come from
diff --git a/lisp/vc/vc-dir.el b/lisp/vc/vc-dir.el
index d75dce77493..db436fa6554 100644
--- a/lisp/vc/vc-dir.el
+++ b/lisp/vc/vc-dir.el
@@ -2027,18 +2027,20 @@ (defun vc-dir (dir &optional backend)
 	  nil t nil nil)))))
   (unless backend
     (setq backend (vc-responsible-backend dir)))
-  (let (pop-up-windows)		      ; based on cvs-examine; bug#6204
-    (pop-to-buffer (vc-dir-prepare-status-buffer "*vc-dir*" dir backend)))
-  (if (derived-mode-p 'vc-dir-mode)
-      (vc-dir-refresh)
-    ;; FIXME: find a better way to pass the backend to `vc-dir-mode'.
-    (let ((use-vc-backend backend))
-      (vc-dir-mode)
-      ;; Activate the backend-specific minor mode, if any.
-      (when-let* ((minor-mode
-                   (intern-soft (format "vc-dir-%s-mode"
-                                        (downcase (symbol-name backend))))))
-        (funcall minor-mode 1)))))
+  (let ((pop-up-windows)		      ; based on cvs-examine; bug#6204
+        (buffer (vc-dir-prepare-status-buffer "*vc-dir*" dir backend)))
+    (with-current-buffer buffer
+      (if (derived-mode-p 'vc-dir-mode)
+          (vc-dir-refresh)
+        ;; FIXME: find a better way to pass the backend to `vc-dir-mode'.
+        (let ((use-vc-backend backend))
+          (vc-dir-mode)
+          ;; Activate the backend-specific minor mode, if any.
+          (when-let* ((minor-mode
+                       (intern-soft (format "vc-dir-%s-mode"
+                                            (downcase (symbol-name backend))))))
+            (funcall minor-mode 1)))))
+    (pop-to-buffer buffer)))
 
 (defun vc-default-dir-extra-headers (_backend _dir)
   ;; Be loud by default to remind people to add code to display
-- 
2.47.3