(cmd_error_internal): Use empty_unibyte_string.

diff --git a/src/keyboard.c b/src/keyboard.c
index ab2d50ad0ea62eb6b2c7f08a780a5e216f8f1fd5..1837958dcfd75a28246b75d7acffd5a41e759e27 100644 (file)
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -1249,7 +1249,7 @@ cmd_error_internal (data, context)
   /* Use user's specified output function if any.  */
   if (!NILP (Vcommand_error_function))
     call3 (Vcommand_error_function, data,
-          build_string (context ? context : ""),
+          context ? build_string (context) : empty_unibyte_string,
           Vsignaling_function);
   /* If the window system or terminal frame hasn't been initialized
      yet, or we're not interactive, write the message to stderr and exit.  */