valgrind: memleak when sidebar open in writer on close

==3768== 512 bytes in 1 blocks are possibly lost in loss record 25,532 of 28,010
==3768==    at 0x4A06965: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==3768==    by 0xB52FA41: __gnu_cxx::new_allocator<bool>::allocate(unsigned long, void const*) (new_allocator.h:104)
==3768==    by 0xB52EC00: std::__cxx1998::_Deque_base<bool, std::allocator<bool> >::_M_allocate_node() (stl_deque.h:533)
==3768==    by 0xB52DE4E: std::__cxx1998::_Deque_base<bool, std::allocator<bool> >::_M_create_nodes(bool**, bool**) (stl_deque.h:627)
==3768==    by 0xB52C624: std::__cxx1998::_Deque_base<bool, std::allocator<bool> >::_M_initialize_map(unsigned long) (stl_deque.h:601)
==3768==    by 0xB52ACA0: std::__cxx1998::_Deque_base<bool, std::allocator<bool> >::_Deque_base(std::allocator<bool> const&, unsigned long) (stl_deque.h:461)
==3768==    by 0xB5296D3: std::__cxx1998::deque<bool, std::allocator<bool> >::deque(std::allocator<bool> const&) (stl_deque.h:791)
==3768==    by 0xB52840E: std::__debug::deque<bool, std::allocator<bool> >::deque(std::allocator<bool> const&) (deque:73)
==3768==    by 0xB52786B: framework::UndoManagerHelper_Impl::UndoManagerHelper_Impl(framework::IUndoManagerImplementation&) (undomanagerhelper.cxx:221)
==3768==    by 0xB525882: framework::UndoManagerHelper::UndoManagerHelper(framework::IUndoManagerImplementation&) (undomanagerhelper.cxx:879)
==3768==    by 0x6872683: sfx2::DocumentUndoManager_Impl::DocumentUndoManager_Impl(sfx2::DocumentUndoManager&) (docundomanager.cxx:88)
==3768==    by 0x6870FB6: sfx2::DocumentUndoManager::DocumentUndoManager(SfxBaseModel&) (docundomanager.cxx:227)
==3768==    by 0x687A272: SfxBaseModel::getUndoManager() (sfxbasemodel.cxx:1677)
==3768==    by 0x260E562A: (anonymous namespace)::getUndoManager(com::sun::star::uno::Reference<com::sun::star::frame::XFrame> const&) (PagePropertyPanel.cxx:74)
==3768==    by 0x260E6C60: sw::sidebar::PagePropertyPanel::PagePropertyPanel(Window*, com::sun::star::uno::Reference<com::sun::star::frame::XFrame> const&, SfxBindings*) (PagePropertyPanel.cxx:189)
==3768==    by 0x260E593C: sw::sidebar::PagePropertyPanel::Create(Window*, com::sun::star::uno::Reference<com::sun::star::frame::XFrame> const&, SfxBindings*) (PagePropertyPanel.cxx:101)

The SfxBaseModel creates the DocumentUndoManager on demand at
sfx2/source/doc/sfxbasemodel.cxx:1685

m_pDocumentUndoManager is a rtl::Reference but debugging into the
acquire/release I see that the
DocumentUndoManager::acquire/DocumentUndoManager::release forward to those of
SfxModelSubComponent which forward them to its rModel without doing anything
else, so the implementations of
DocumentUndoManager::acquire/DocumentUndoManager::release don't actually do
anything directly to the DocumentUndoManager itself so there is nothing that
will really release it.

Either the rModel needs to explicitly destroy it somehow, given that the
acquire/release delegate responsibility to it, or the whole thing is addled.

I rather feel it's addled, so implement as a normal WeakImplHelper1, but
cowardly in addition also keep acquire/release on the rModel.

Change-Id: Ib52544a9276fd8d9d489ad6b6afda12498cc39fa

include/sfx2/sfxbasemodel.hxx

@@ -916,9 +916,8 @@ protected:
     }
     virtual ~SfxModelSubComponent();
 
-    // helpers for implementing XInterface - delegates ref counting to the SfxBaseModel
-    void acquire()  {   m_rModel.acquire(); }
-    void release()  {   m_rModel.release(); }
+    void acquireModel()  { m_rModel.acquire(); }
+    void releaseModel()  { m_rModel.release(); }
 
     bool isDisposed() const {   return m_rModel.IsDisposed();   }
 

sfx2/source/doc/docundomanager.cxx

@@ -19,12 +19,12 @@
 
 
 #include "docundomanager.hxx"
+#include <cppuhelper/weak.hxx>
 #include <sfx2/sfxbasemodel.hxx>
 #include <sfx2/objsh.hxx>
 #include <sfx2/viewfrm.hxx>
 #include <sfx2/viewsh.hxx>
 #include <sfx2/bindings.hxx>
-
 #include <com/sun/star/lang/XComponent.hpp>
 
 #include <comphelper/anytostring.hxx>
@@ -228,12 +228,10 @@ namespace sfx2
     {
     }
 
-
     DocumentUndoManager::~DocumentUndoManager()
     {
     }
 
-
     void DocumentUndoManager::disposing()
     {
         m_pImpl->disposing();
@@ -247,15 +245,17 @@ namespace sfx2
     }
 
 
-    void SAL_CALL DocumentUndoManager::acquire(  ) throw ()
+    void SAL_CALL DocumentUndoManager::acquire() throw()
     {
-        SfxModelSubComponent::acquire();
+        OWeakObject::acquire();
+        SfxModelSubComponent::acquireModel();
     }
 
 
-    void SAL_CALL DocumentUndoManager::release(  ) throw ()
+    void SAL_CALL DocumentUndoManager::release() throw()
     {
-        SfxModelSubComponent::release();
+        SfxModelSubComponent::releaseModel();
+        OWeakObject::release();
     }
 
 

sfx2/source/inc/docundomanager.hxx

@@ -37,8 +37,7 @@ namespace sfx2
 
     //= DocumentUndoManager
 
-    typedef ::cppu::ImplHelper1 <   ::com::sun::star::document::XUndoManager
-                                >   DocumentUndoManager_Base;
+    typedef ::cppu::WeakImplHelper1 <css::document::XUndoManager> DocumentUndoManager_Base;
     struct DocumentUndoManager_Impl;
     class DocumentUndoManager   :public DocumentUndoManager_Base
                                 ,public SfxModelSubComponent