Merge from origin/emacs-27

09eed01afb Wrap some set-auto-mode calls with delay-mode-hooks (bug#3...
4a0a114505 Support ido-vertical-mode better
ef5fba9f40 Fix faces tab-bar and tab-line.
831508422e Cater for 3-argument version of pthread_setname_np
f27187f963 Clarify lexvar restrictions for add-to-ordered-list, add-t...
32763dac46 Replace add-to-list to lexical variable with push (bug#39373)
d07f177382 Clarify add-to-list documentation (bug#39373)
d3d2ea927c MH-E: alter content in mh-display-msg, not mh-show-mode
db7fa2546f Update documentation for mh-show-mode-hook
d10be6bf28 Example goto-addr hook: MH-E already uses goto-address

# Conflicts:
#	etc/NEWS

2 files changed, 6 insertions, 2 deletions

diff --git a/lisp/vc/diff-mode.el b/lisp/vc/diff-mode.el
index 2dbab802086..d61c363c821 100644
--- a/lisp/vc/diff-mode.el
+++ b/lisp/vc/diff-mode.el
@@ -2719,7 +2719,9 @@ hunk text is not found in the source file."
     (cl-assert (null buffer-file-name))
     (let ((enable-local-variables :safe) ;; to find `mode:'
           (buffer-file-name file))
-      (set-auto-mode)
+      ;; Don't run hooks that might assume buffer-file-name
+      ;; really associates buffer with a file (bug#39190).
+      (delay-mode-hooks (set-auto-mode))
       ;; FIXME: Is this really worth the trouble?
       (when (and (fboundp 'generic-mode-find-file-hook)
                  (memq #'generic-mode-find-file-hook
diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
index f64b6c06310..ec252b74d47 100644
--- a/lisp/vc/vc.el
+++ b/lisp/vc/vc.el
@@ -2098,7 +2098,9 @@ Unlike `vc-find-revision-save', doesn't save the buffer to the file."
                     ;; For non-interactive, skip any questions
                     (let ((enable-local-variables :safe) ;; to find `mode:'
                           (buffer-file-name file))
-                      (ignore-errors (set-auto-mode)))
+                      ;; Don't run hooks that might assume buffer-file-name
+                      ;; really associates buffer with a file (bug#39190).
+                      (ignore-errors (delay-mode-hooks (set-auto-mode))))
                   (normal-mode))
                 (set-buffer-modified-p nil)
                 (setq buffer-read-only t))