DOCX export: fix page border spacing in case of headers/footers

It is clear that Word/Writer has different page margin / border spacing
models: in Word, the page margin includes everything and border spacing
is a subset of that, in Writer the real distance between the body frame
and the page frame is the sum of the two.

What was less clear is what headers / footers add to this mix. It turns
out that in case we have a header as well, then for large borders, we
need to count the difference of the page frame and the header frame, not
the difference of the page frame and the body frame.

Change-Id: I3c828eeec2df461985110064ab0bf21b36594095

2 files changed, 17 insertions, 2 deletions

diff --git a/sw/qa/extras/ooxmlexport/ooxmlexport5.cxx b/sw/qa/extras/ooxmlexport/ooxmlexport5.cxx
index fd9341c5f054..26f521b0873c 100644
--- a/sw/qa/extras/ooxmlexport/ooxmlexport5.cxx
+++ b/sw/qa/extras/ooxmlexport/ooxmlexport5.cxx
@@ -702,9 +702,15 @@ DECLARE_OOXMLEXPORT_TEST(testFD083057, "fdo83057.docx")
 
 DECLARE_OOXMLEXPORT_TEST(testHeaderBorder, "header-border.docx")
 {
-    // This was 0, as header margin was lost during import.
     if (xmlDocPtr pXmlDoc = parseExport("word/document.xml"))
+    {
+        // This was 0, as header margin was lost during import.
         assertXPath(pXmlDoc, "//w:pgMar", "header", "720");
+        // This was 33: 33 points -> 660 twips. We counted 900 - 240 (distance
+        // of page and body frame) instead of 720 - 240 (distance of page and
+        // header frame).
+        assertXPath(pXmlDoc, "//w:pgBorders/w:top", "space", "24");
+    }
 }
 
 CPPUNIT_PLUGIN_IMPLEMENT();
diff --git a/sw/source/filter/ww8/docxattributeoutput.cxx b/sw/source/filter/ww8/docxattributeoutput.cxx
index cacbe97beb80..4e4dccd175ba 100644
--- a/sw/source/filter/ww8/docxattributeoutput.cxx
+++ b/sw/source/filter/ww8/docxattributeoutput.cxx
@@ -5499,8 +5499,17 @@ void DocxAttributeOutput::SectionPageBorders( const SwFrmFmt* pFmt, const SwFrmF
             aOutputBorderOptions.aShadowLocation = pShadowItem->GetLocation();
         }
 
+        // By top margin, impl_borders() means the distance between the top of the page and the header frame.
+        PageMargins aMargins = m_pageMargins;
+        HdFtDistanceGlue aGlue(pFmt->GetAttrSet());
+        if (aGlue.HasHeader())
+            aMargins.nPageMarginTop = aGlue.dyaHdrTop;
+        // Ditto for bottom margin.
+        if (aGlue.HasFooter())
+            aMargins.nPageMarginBottom = aGlue.dyaHdrBottom;
+
         std::map<sal_uInt16, css::table::BorderLine2> aEmptyMap; // empty styles map
-        impl_borders( m_pSerializer, rBox, aOutputBorderOptions, &m_pageMargins,
+        impl_borders( m_pSerializer, rBox, aOutputBorderOptions, &aMargins,
                       aEmptyMap );
 
         m_pSerializer->endElementNS( XML_w, XML_pgBorders );