(set-auto-mode): When just-from-file-name is set, don't

actually switch modes if the new mode is the same as the current one.

1 files changed, 7 insertions, 1 deletions

diff --git a/lisp/files.el b/lisp/files.el
index ea718410bd3..60a45aac4b5 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -1391,7 +1391,13 @@ and we don't even do that unless it would come from the file name."
                               keep-going nil)))
                   (setq alist (cdr alist))))
               (if mode
-                  (funcall mode)
+                  ;; When JUST-FROM-FILE-NAME is set,
+                  ;; we are working on behalf of set-visited-file-name.
+                  ;; In that case, if the major mode specified is the
+                  ;; same one we already have, don't actually reset it.
+                  ;; We don't want to lose minor modes such as Font Lock.
+                  (unless (and just-from-file-name (eq mode major-mode))
+                    (funcall mode))
                 ;; If we can't deduce a mode from the file name,
                 ;; look for an interpreter specified in the first line.
                 ;; As a special case, allow for things like "#!/bin/env perl",