tdf#107969: use proper serializer for VML in footnotes/endnotes

Change-Id: Ie0e062fab0ae1a63094655cc0f6bee958b4c1087
Reviewed-on: https://gerrit.libreoffice.org/55978
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

sw/qa/extras/ooxmlexport/ooxmlexport11.cxx

@@ -388,6 +388,13 @@ DECLARE_OOXMLEXPORT_TEST(testTdf116801, "tdf116801.docx")
     CPPUNIT_ASSERT_EQUAL(OUString("D1"), xCell->getString());
 }
 
+DECLARE_OOXMLEXPORT_TEST(testTdf107969, "tdf107969.docx")
+{
+    // A VML object in a footnote's tracked changes caused write past end of document.xml at export to docx.
+    // After that, importing after export failed with
+    // SAXParseException: '[word/document.xml line 2]: Extra content at the end of the document', Stream 'word/document.xml'.
+}
+
 CPPUNIT_PLUGIN_IMPLEMENT();
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sw/source/filter/ww8/docxexport.cxx

@@ -681,11 +681,14 @@ void DocxExport::WriteFootnotesEndnotes()
         m_pAttrOutput->SetSerializer( pFootnotesFS );
         // tdf#99227
         m_pSdrExport->setSerializer( pFootnotesFS );
+        // tdf#107969
+        m_pVMLExport->SetFS(pFootnotesFS);
 
         // do the work
         m_pAttrOutput->FootnotesEndnotes( true );
 
         // switch the serializer back
+        m_pVMLExport->SetFS(m_pDocumentFS);
         m_pSdrExport->setSerializer( m_pDocumentFS );
         m_pAttrOutput->SetSerializer( m_pDocumentFS );
     }
@@ -705,11 +708,14 @@ void DocxExport::WriteFootnotesEndnotes()
         m_pAttrOutput->SetSerializer( pEndnotesFS );
         // tdf#99227
         m_pSdrExport->setSerializer( pEndnotesFS );
+        // tdf#107969
+        m_pVMLExport->SetFS(pEndnotesFS);
 
         // do the work
         m_pAttrOutput->FootnotesEndnotes( false );
 
         // switch the serializer back
+        m_pVMLExport->SetFS(m_pDocumentFS);
         m_pSdrExport->setSerializer( m_pDocumentFS );
         m_pAttrOutput->SetSerializer( m_pDocumentFS );
     }