Fix listing names with escapable characters

* imap4d/io.c (io_send_qstring): Fix condition
* imap4d/list.c (list_fun): Use io_send_qstring to print names.
* imap4d/lsub.c (imap4d_lsub): Likewise.

@@ -234,15 +234,14 @@ io_sendf (const char *format, ...)
 }
 
 /* Send NIL if empty string, change the quoted string to a literal if the
-   string contains: double quotes, CR, LF, and '/'.  CR, LF will be changed
+   string contains: double quotes, CR, LF, and '\\'.  CR, LF will be changed
    to spaces.  */
 int
 io_send_qstring (const char *buffer)
 {
   if (buffer == NULL || *buffer == '\0')
     return io_sendf ("NIL");
-  if (strchr (buffer, '"') || strchr (buffer, '\r') || strchr (buffer, '\n')
-      || strchr (buffer, '\\'))
+  if (strpbrk (buffer, "\"\r\n\\"))
     {
       char *s;
       int ret;

@@ -93,7 +93,10 @@ list_fun (mu_folder_t folder, struct mu_list_response *resp, void *data)
   else if (is_atom (name))
     io_sendf ("%s\n", name);
   else
-    io_sendf ("\"%s\"\n", name);
+    {
+      io_send_qstring (name);
+      io_sendf ("\n", name);
+    }
   return 0;
 }
 

@@ -65,8 +65,12 @@ imap4d_lsub (struct imap4d_session *session,
 	  mu_iterator_current_kv (itr, (const void **)&name, (void**)&val);
 
 	  if (mu_imap_wildmatch (pattern, name, MU_HIERARCHY_DELIMITER) == 0)
-	    io_untagged_response (RESP_NONE, "LSUB () \"%c\" \"%s\"",
-				  MU_HIERARCHY_DELIMITER, name);
+	    {
+	      mu_stream_printf (iostream, "* LSUB () \"%c\" ",
+				MU_HIERARCHY_DELIMITER);
+	      io_send_qstring (name);
+	      io_sendf ("\n");
+	    }
 	}
     }
   else