Tweak Fdirectory_append for efficiency

* src/fileio.c (Fdirectory_append): Make slightly more efficient.

diff --git a/src/fileio.c b/src/fileio.c
index a4f08383776a4c023c1fbdd5967a6df6fd3930b9..ddce4723f4277a23a449ec705151947010d42c91 100644 (file)
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -795,7 +795,8 @@ usage: (record DIRECTORY &rest COMPONENTS) */)
       for (i = 0; i < nargs; i++)
        {
          Lisp_Object arg = args[i];
-         if (STRING_MULTIBYTE (arg))
+         /* Use multibyte or all-ASCII strings as is. */
+         if (STRING_MULTIBYTE (arg) || SCHARS (arg) == SBYTES (arg))
            elements[i] = arg;
          else
            elements[i] = make_multibyte_string (SSDATA (arg), SCHARS (arg),