* lisp/international/mule-cmds.el (encode-coding-char): Fix ASCII case

Don't bother with string-as-multibyte since `string` already returns
multibyte when needed.  Don't forget to encode when the string is
ASCII, e.g. for ebcdic case and to make sure we always return
a unibyte string.

* test/lisp/international/mule-tests.el (mule-cmds-tests--encode-ebcdic):
New test.

1 files changed, 4 insertions, 0 deletions

diff --git a/test/lisp/international/mule-tests.el b/test/lisp/international/mule-tests.el
index 4c937caa142..678cbc29738 100644
--- a/test/lisp/international/mule-tests.el
+++ b/test/lisp/international/mule-tests.el
@@ -36,6 +36,10 @@
                      (find-auto-coding "" (buffer-size)))
                    '(utf-8 . :coding)))))
 
+(ert-deftest mule-cmds-tests--encode-ebcdic ()
+  (should (equal (encode-coding-char ?a 'ebcdic-int) "\201"))
+  (should (not (multibyte-string-p (encode-coding-char ?a 'utf-8)))))
+
 ;; Stop "Local Variables" above causing confusion when visiting this file.