tdf#147731 sw: fix memory leak in SwDoc::CopyPageDesc()

Commit 963de9feb37105560fde14b44d992e47f341bb5b "sw: fix issue with
copying stashed frame format" fixed the actual bug here, but introduced
a new memory leak.

This causes an assert in CppunitTest_uiwriter3:
cppunittester: svl/source/items/itempool.cxx:779: void SfxItemPool::Remove(const SfxPoolItem&): Assertion `rItem.GetRefCount() && "RefCount == 0, Remove impossible"' failed.

The assert happens only when this is backported to the libreoffice-7-6
branch, because commit ab7c81f55621d7b0d1468c63305163016dd78837 "ITEM:
Get away from classic 'poolable' Item flag" removed the assert.

The problem is that a SwFormatFrameSize inside a footer SwFrameFormat is
leaked 4 times, because 4 SwFrameFormats are leaked; the leak is that
SwDoc::CopyPageDesc() creates a new pNewFormat, passed it to
StashFrameFormat(), which copies it but doesn't free it.

There is also a usage of std::shared_ptr here that is very questionable;
SwFrameFormat should never be shared between different SwPageDesc.

(regression from commit b802ab694a8a7357d4657f3e11b571144fa7c7bf)

Change-Id: I44133bc5e6789a51ce064f1aa5ea8b325224365b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/163854
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/sw/inc/pagedesc.hxx b/sw/inc/pagedesc.hxx
index 136117114b30..3ec919ce3c83 100644
--- a/sw/inc/pagedesc.hxx
+++ b/sw/inc/pagedesc.hxx
@@ -151,9 +151,9 @@ class SW_DLLPUBLIC SwPageDesc final
 
     struct StashedPageDesc
     {
-        std::shared_ptr<SwFrameFormat> m_pStashedFirst;
-        std::shared_ptr<SwFrameFormat> m_pStashedLeft;
-        std::shared_ptr<SwFrameFormat> m_pStashedFirstLeft;
+        std::optional<SwFrameFormat> m_oStashedFirst;
+        std::optional<SwFrameFormat> m_oStashedLeft;
+        std::optional<SwFrameFormat> m_oStashedFirstLeft;
     };
 
     mutable StashedPageDesc m_aStashedHeader;