From caf15ff01e7ebd83b09e7ad6e0446b24d0041beb Mon Sep 17 00:00:00 2001
From: =?utf8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Mon, 17 Oct 2016 12:22:44 -0400
Subject: [PATCH] man: add a note that NULL "s" arg for sd_bus_message_append

---
 man/sd_bus_message_append.xml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/man/sd_bus_message_append.xml b/man/sd_bus_message_append.xml
index 77fce02..c222d0f 100644
--- a/man/sd_bus_message_append.xml
+++ b/man/sd_bus_message_append.xml
@@ -169,6 +169,11 @@
       </tgroup>
     </table>
 
+    <para>For types "s" and "g" (unicode string or signature), the pointer may be
+    <constant>NULL</constant>, which is equivalent to an empty string. See
+    <citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    for the precise interpretation of those and other types.</para>
+
   </refsect1>
 
   <refsect1>
-- 
2.7.4