(Fformat_mode_line, syms_of_xdisp): Use empty_unibyte_string.

diff --git a/src/xdisp.c b/src/xdisp.c
index 55ab39fd5af22022b5cba69510c8cd3eb9e95237..f3e1aa1112c1ed1693972c5af970a85bcc8dc7d3 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -17342,7 +17342,7 @@ are the selected window and the window's buffer).  */)
   CHECK_BUFFER (buffer);
 
   if (NILP (format))
-    return build_string ("");
+    return empty_unibyte_string;
 
   if (no_props)
     face = Qnil;
@@ -17400,7 +17400,7 @@ are the selected window and the window's buffer).  */)
     {
       mode_line_string_list = Fnreverse (mode_line_string_list);
       str = Fmapconcat (intern ("identity"), mode_line_string_list,
-                       make_string ("", 0));
+                       empty_unibyte_string);
     }
 
   unbind_to (count, Qnil);
@@ -24081,7 +24081,7 @@ and is used only on frames for which no explicit name has been set
     = Vframe_title_format
     = Fcons (intern ("multiple-frames"),
             Fcons (build_string ("%b"),
-                   Fcons (Fcons (empty_string,
+                   Fcons (Fcons (empty_unibyte_string,
                                  Fcons (intern ("invocation-name"),
                                         Fcons (build_string ("@"),
                                                Fcons (intern ("system-name"),