2 files changed, 6 insertions, 2 deletions

diff --git a/lisp/international/mule-cmds.el b/lisp/international/mule-cmds.el
index cbe548c2ccf..378cbc9badd 100644
--- a/lisp/international/mule-cmds.el
+++ b/lisp/international/mule-cmds.el
@@ -418,7 +418,10 @@ To prefer, for instance, utf-8, say the following:
     (if (memq eol-type '(0 1 2))
         (setq base
               (coding-system-change-eol-conversion base eol-type)))
-    (set-default-coding-systems base)))
+    (set-default-coding-systems base)
+    (if (called-interactively-p 'interactive)
+        (or (eq base default-file-name-coding-system)
+            (message "The default value of `file-name-coding-system' was not changed because the specified coding system is not suitable for file names.")))))
 
 (defvar sort-coding-systems-predicate nil
   "If non-nil, a predicate function to sort coding systems.
diff --git a/lisp/international/mule.el b/lisp/international/mule.el
index 17163071d3f..d4dd4e4cf24 100644
--- a/lisp/international/mule.el
+++ b/lisp/international/mule.el
@@ -1668,6 +1668,7 @@ in-place."
 
 ;;; FILE I/O
 
+;; TODO many elements of this list are also in inhibit-local-variables-regexps.
 (defcustom auto-coding-alist
   ;; .exe and .EXE are added to support archive-mode looking at DOS
   ;; self-extracting exe archives.
@@ -1677,7 +1678,7 @@ arc\\|zip\\|lzh\\|lha\\|zoo\\|[jew]ar\\|xpi\\|rar\\|7z\\|\
 ARC\\|ZIP\\|LZH\\|LHA\\|ZOO\\|[JEW]AR\\|XPI\\|RAR\\|7Z\\)\\'"
      . no-conversion-multibyte)
     ("\\.\\(exe\\|EXE\\)\\'" . no-conversion)
-    ("\\.\\(sx[dmicw]\\|odt\\|tar\\|tgz\\)\\'" . no-conversion)
+    ("\\.\\(sx[dmicw]\\|odt\\|tar\\|t[bg]z\\)\\'" . no-conversion)
     ("\\.\\(gz\\|Z\\|bz\\|bz2\\|xz\\|gpg\\)\\'" . no-conversion)
     ("\\.\\(jpe?g\\|png\\|gif\\|tiff?\\|p[bpgn]m\\)\\'" . no-conversion)
     ("\\.pdf\\'" . no-conversion)