(Fsingle_key_description): Create a multibyte string

only if necessary.

1 files changed, 12 insertions, 8 deletions

diff --git a/src/keymap.c b/src/keymap.c
index a1f0de1c09a..f96c109c9cd 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -1959,14 +1959,18 @@ around function keys and event symbols.")
         }
       else
         {
-          char tem[KEY_DESCRIPTION_SIZE];
-          int len;
-
-          *push_key_description (XUINT (key), tem, 1) = 0;
-          len = strlen (tem);
-          return make_multibyte_string (tem,
-                                        multibyte_chars_in_text (tem, len),
-                                        len);
+          char tem[KEY_DESCRIPTION_SIZE], *end;
+          int nbytes, nchars;
+          Lisp_Object string;
+
+          end = push_key_description (XUINT (key), tem, 1);
+          nbytes = end - tem;
+          nchars = multibyte_chars_in_text (tem, nbytes);
+          if (nchars == nbytes)
+            string = build_string (tem);
+          else
+            string = make_multibyte_string (tem, nchars, nbytes);
+          return string;
         }
     }
   else if (SYMBOLP (key))       /* Function key or event-symbol */