Minor changes

@@ -220,7 +220,7 @@ SCM_DEFINE_PUBLIC (scm_mu_mailbox_open, "mu-mailbox-open", 2, 0, 0,
   int status;
   SCM ret;
   
-  SCM_ASSERT (scm_is_string (url), url, SCM_ARG1, FUNC_NAME);
+  SCM_ASSERT (scm_is_bool (url) || scm_is_string (url), url, SCM_ARG1, FUNC_NAME);
   SCM_ASSERT (scm_is_string (mode), mode, SCM_ARG2, FUNC_NAME);
   
   scm_dynwind_begin (0);
@@ -247,8 +247,20 @@ SCM_DEFINE_PUBLIC (scm_mu_mailbox_open, "mu-mailbox-open", 2, 0, 0,
   if (mode_bits & MU_STREAM_READ && mode_bits & MU_STREAM_WRITE)
     mode_bits = (mode_bits & ~(MU_STREAM_READ | MU_STREAM_WRITE)) | MU_STREAM_RDWR;
 
-  mode_str = scm_to_locale_string (url);
-  scm_dynwind_free (mode_str);
+  if (scm_is_bool (url))
+    {
+      if (url == SCM_BOOL_F)
+	mode_str = NULL;
+      else
+	mu_scm_error (FUNC_NAME, EINVAL,
+		      "value #t for URL is reserved for future use",
+		      scm_list_1 (url));
+    }
+  else
+    {
+      mode_str = scm_to_locale_string (url);
+      scm_dynwind_free (mode_str);
+    }
   
   status = mu_mailbox_create_default (&mbox, mode_str);
   if (status)

@@ -111,6 +111,7 @@ SCM_DEFINE_PUBLIC (scm_mu_register_format, "mu-register-format", 0, 0, 1,
 {
   int status;
 
+  SCM_VALIDATE_REST_ARGUMENT (rest);
   if (scm_is_null (rest))
     {
       status = register_format (NULL);

@@ -513,7 +513,7 @@ mail_send (int argc, char **argv)
 		  mode = hp->mode;
 		  if (mu_header_sget_value (env.header, hp->name, NULL) == 0)
 		    mode = COMPOSE_REPLACE;
-		  compose_header_set (&env, hp->name, hp->value, hp->mode);
+		  compose_header_set (&env, hp->name, hp->value, mode);
 		}
 	      mu_iterator_destroy (&itr);
 	    }

@@ -27,6 +27,7 @@ exec ${GUILE-guile} -l $0 -c "(apply $main (list (command-line)))" "$@"
 
 (use-modules (ice-9 getopt-long)
 	     (ice-9 rdelim)
+	     (ice-9 eval-string)
 	     (srfi srfi-1)
 	     (mailutils mailutils))
 
@@ -190,7 +191,7 @@ for any corresponding short options.
     guimb-module)
 
 (define-macro (bound? name)
-  `(and (module-defined? guimb-module ',name)
+  `(and (module-defined? (get-module) ',name)
 	(procedure? ,name)))
 
 (define (guimb-parse-command-line cmdline)
@@ -219,17 +220,12 @@ for any corresponding short options.
     (if (not output-mailbox-mode)
 	(set! output-mailbox-mode (if (null? input-mailbox-names) "wr" "a")))
     
-    (cond
-     (user-name
-      (set! output-mailbox
-	    (mu-mailbox-open
-	     (if (string? user-name)
-		 (string-append "%" user-name)
-		 "")
-	     output-mailbox-mode)))
-     (output-mailbox-name
-      (set! output-mailbox (mu-mailbox-open output-mailbox-name
-					    output-mailbox-mode))))
+    (if (and (not output-mailbox-name) user-name)
+	(set! output-mailbox-name (if (string? user-name)
+			 (string-append "%" user-name)
+			 #f)))
+    (set! output-mailbox (mu-mailbox-open output-mailbox-name
+						    output-mailbox-mode))
 ;    (write output-mailbox)(newline)
 
     (if source-file-name