Wrap some set-auto-mode calls with delay-mode-hooks (bug#39190)

* lisp/gnus/mm-view.el (mm-display-inline-fontify):
* lisp/vc/diff-mode.el (diff-syntax-fontify-props):
* lisp/vc/vc.el (vc-find-revision-no-save):
Add delay-mode-hooks around set-auto-mode calls
to not run hooks that might assume buffer-file-name
really associates buffer with a file.

1 files changed, 3 insertions, 1 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