sd-event: add sd_event_source_disable_unrefp() too

I do not have any immediate use for it, but let's add it for completeness.

man/rules/meson.build

@@ -446,6 +446,7 @@ manpages = [
  ['sd_event_source_unref',
   '3',
   ['sd_event_source_disable_unref',
+   'sd_event_source_disable_unrefp',
    'sd_event_source_ref',
    'sd_event_source_unrefp'],
   ''],

man/sd_event_source_unref.xml

@@ -20,6 +20,7 @@
     <refname>sd_event_source_unrefp</refname>
     <refname>sd_event_source_ref</refname>
     <refname>sd_event_source_disable_unref</refname>
+    <refname>sd_event_source_disable_unrefp</refname>
 
     <refpurpose>Increase or decrease event source reference counters</refpurpose>
   </refnamediv>
@@ -47,6 +48,11 @@
         <funcdef>sd_event_source* <function>sd_event_source_disable_unref</function></funcdef>
         <paramdef>sd_event_source *<parameter>source</parameter></paramdef>
       </funcprototype>
+
+      <funcprototype>
+        <funcdef>void <function>sd_event_source_disable_unrefp</function></funcdef>
+        <paramdef>sd_event_source **<parameter>source</parameter></paramdef>
+      </funcprototype>
     </funcsynopsis>
   </refsynopsisdiv>
 
@@ -94,6 +100,12 @@
     <function>sd_event_source_unref()</function>. This ensures that the source is disabled before the local
     reference to it is lost. The <parameter>source</parameter> parameter is allowed to be
     <constant>NULL</constant>.</para>
+
+    <para><function>sd_event_source_disable_unrefp()</function> is similar to
+    <function>sd_event_source_unrefp()</function>, but in addition disables the source first. This call is
+    useful in conjunction with GCC's and LLVM's
+    <ulink url="https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html">Clean-up Variable
+    Attribute</ulink>. Note that this function is defined as inline function.</para>
   </refsect1>
 
   <refsect1>

src/systemd/sd-event.h

@@ -150,6 +150,7 @@ int sd_event_source_set_floating(sd_event_source *s, int b);
 /* Define helpers so that __attribute__((cleanup(sd_event_unrefp))) and similar may be used. */
 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event, sd_event_unref);
 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_unref);
+_SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_disable_unref);
 
 _SD_END_DECLARATIONS;