fdo#80927: css.office.Quickstart should be single-instance service.

Incorrectly converted in a384b21c
where SFX_IMPL_ONEINSTANCEFACTORY was used.

AFAICS it's the first converted single-instance service which implements
css::lang::XInitialization. That's kind of strange but can do its job.

sbergman@redhat.com:  Three things were necessary in order to not call the
~ShutdownIcon code too late during exit now:

* Move the relevant code from ~ShutdownIcon to ShutdownIcon::disposing.

* Add a dummy <singleton name="com.sun.star.office.theQuickstart"/> so the
  service manager will eventually dispose the (single) instance.

* In
  cppuhelper::ServiceManager::Data::Implementation::createInstanceWithArguments
  do not shortcut updateDisposeSingleton in that odd case of calling
  createInstanceWithArguments on an implementation that (effectively) is a
  singleton (as otherwise the service manager would still not dispose it).  It
  looks to me like that "return inst;" was an inadvertent leftover in
  874c4818 "Simplify service manager's tracking
  of singletons" and wasn't intended to serve some subtle purpose.

Change-Id: Icd4d3168ec0bbb820b17ac321fe897ac9f9ce7fc

cppuhelper/source/servicemanager.cxx

@@ -711,7 +711,6 @@ cppuhelper::ServiceManager::Data::Implementation::createInstanceWithArguments(
         if (init.is()) {
             init->initialize(arguments);
         }
-        return inst;
     } else if (factory1.is()) {
         inst = factory1->createInstanceWithArgumentsAndContext(
             arguments, context);

sfx2/source/appl/shutdownicon.cxx

@@ -600,6 +600,8 @@ void SAL_CALL ShutdownIcon::disposing()
 {
     m_xContext.clear();
     m_xDesktop.clear();
+
+    deInitSystray();
 }
 
 
@@ -903,12 +905,31 @@ void SAL_CALL ShutdownIcon::setFastPropertyValue(       ::sal_Int32
     return aValue;
 }
 
+namespace {
+
+struct Instance {
+    explicit Instance(
+        css::uno::Reference<css::uno::XComponentContext> const & context):
+        instance(static_cast<cppu::OWeakObject *>(new ShutdownIcon(context)))
+    {}
+
+    rtl::Reference<css::uno::XInterface> instance;
+};
+
+struct Singleton:
+    public rtl::StaticWithArg<
+        Instance, css::uno::Reference<css::uno::XComponentContext>, Singleton>
+{};
+
+}
+
 extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface * SAL_CALL
 com_sun_star_comp_desktop_QuickstartWrapper_get_implementation(
     css::uno::XComponentContext *context,
     css::uno::Sequence<css::uno::Any> const &)
 {
-    return cppu::acquire(new ShutdownIcon(context));
+    return cppu::acquire(static_cast<cppu::OWeakObject *>(
+                Singleton::get(context).instance.get()));
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sfx2/util/sfx.component

@@ -35,6 +35,7 @@
   <implementation name="com.sun.star.comp.desktop.QuickstartWrapper"
       constructor="com_sun_star_comp_desktop_QuickstartWrapper_get_implementation">
     <service name="com.sun.star.office.Quickstart"/>
+    <singleton name="com.sun.star.office.theQuickstart"/>
   </implementation>
   <implementation name="com.sun.star.comp.document.OwnSubFilter"
       constructor="com_sun_star_comp_document_OwnSubFilter_get_implementation">