Minor changes

* mail/mail.c (cli_attach): Exit if unable to attach file.
* mail/mail.h (send_attach_file): Change prototype.
* mail/send.c (send_attach_file): Return int.
(add_body): Honor default_content_type

@@ -146,8 +146,9 @@ cli_attach (struct mu_parseopt *po, struct mu_option *opt, char const *arg)
       arg = NULL;
       fd = 0;
     }
-  send_attach_file (fd, arg, content_filename, content_name,
-		    default_content_type, default_encoding);
+  if (send_attach_file (fd, arg, content_filename, content_name,
+			default_content_type, default_encoding))
+    exit (po->po_exit_error);
 
   free (content_name);
   content_name = NULL;

@@ -263,7 +263,7 @@ extern char *mail_expand_name (const char *name);
 
 extern void send_append_header (char const *text);
 extern void send_append_header2 (char const *name, char const *value, int mode);
-extern void send_attach_file (int fd,
+extern int send_attach_file (int fd,
 			     const char *filename,
 			     const char *content_filename,
 			     const char *content_name,

@@ -324,13 +324,13 @@ attlist_copy (mu_list_t src)
 
 static mu_list_t attachment_list;
 
-void
+int
 send_attach_file (int fd,
 		  const char *realname,
 		  const char *content_filename, const char *content_name,
 		  const char *content_type, const char *encoding)
 {
-  attlist_attach_file (&attachment_list,
+  return attlist_attach_file (&attachment_list,
 			      fd,
 			      realname,
 			      content_filename,
@@ -561,7 +561,9 @@ add_body (mu_message_t inmsg, mu_iterator_t itr, mu_mime_t mime)
     }
   
   /* 4. Add the content type and content ID headers. */
-  mu_header_set_value (outhdr, MU_HEADER_CONTENT_TYPE, "text/plain", 0);
+  mu_header_set_value (outhdr, MU_HEADER_CONTENT_TYPE,
+		       default_content_type ? default_content_type : "text/plain",
+		       0);
   mu_rfc2822_msg_id (0, &p);
   mu_header_set_value (outhdr, MU_HEADER_CONTENT_ID, p, 1);
   free (p);