tdf#123353 XLSX export: fix lost AutoFilter on empty cells

The AutoFilter button was lost during export when only the
rows with empty cells were visible and everything else was
hidden. The filter itself was still active, but the button
itself was gone.

Co-authored-by: Attila Szűcs (NISZ)

Change-Id: Ia0b16bf4f15303d1320081cb62090368a0ce3908
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/101847
Tested-by: László Németh <nemeth@numbertext.org>
Reviewed-by: László Németh <nemeth@numbertext.org>

4 files changed, 32 insertions, 3 deletions

diff --git a/sc/qa/unit/data/xlsx/tdf123353.xlsx b/sc/qa/unit/data/xlsx/tdf123353.xlsx
new file mode 100644
index 000000000000..f37f0724ca98
--- /dev/null
+++ b/sc/qa/unit/data/xlsx/tdf123353.xlsx
diff --git a/sc/qa/unit/subsequent_export-test.cxx b/sc/qa/unit/subsequent_export-test.cxx
index 8172ae52da05..efe44fc22f2b 100644
--- a/sc/qa/unit/subsequent_export-test.cxx
+++ b/sc/qa/unit/subsequent_export-test.cxx
@@ -259,6 +259,7 @@ public:
     void testTdf121718_UseFirstPageNumberXLSX();
     void testHeaderFontStyleXLSX();
     void testTdf135828_Shape_Rect();
+    void testTdf123353();
 
     CPPUNIT_TEST_SUITE(ScExportTest);
     CPPUNIT_TEST(test);
@@ -416,6 +417,7 @@ public:
     CPPUNIT_TEST(testTdf121718_UseFirstPageNumberXLSX);
     CPPUNIT_TEST(testHeaderFontStyleXLSX);
     CPPUNIT_TEST(testTdf135828_Shape_Rect);
+    CPPUNIT_TEST(testTdf123353);
 
     CPPUNIT_TEST_SUITE_END();
 
@@ -5314,6 +5316,7 @@ void ScExportTest::testTdf135828_Shape_Rect()
     CPPUNIT_ASSERT(xDocSh.is());
 
     std::shared_ptr<utl::TempFile> pXPathFile = ScBootstrapFixture::exportTo(&(*xDocSh), FORMAT_XLSX);
+
     xmlDocUniquePtr pDrawing = XPathHelper::parseExport(pXPathFile, m_xSFactory, "xl/drawings/drawing1.xml");
     CPPUNIT_ASSERT(pDrawing);
 
@@ -5321,6 +5324,24 @@ void ScExportTest::testTdf135828_Shape_Rect()
     assertXPath(pDrawing, "/xdr:wsDr/xdr:twoCellAnchor/xdr:sp/xdr:spPr/a:xfrm/a:ext", "cy", "1990440"); // height
 }
 
+void ScExportTest::testTdf123353()
+{
+    ScDocShellRef xShell = loadDoc("tdf123353.", FORMAT_XLSX);
+    CPPUNIT_ASSERT(xShell.is());
+
+    ScDocShellRef xDocSh = saveAndReload(&(*xShell), FORMAT_XLSX);
+    CPPUNIT_ASSERT(xDocSh.is());
+
+    std::shared_ptr<utl::TempFile> pXPathFile = ScBootstrapFixture::exportTo(&(*xDocSh), FORMAT_XLSX);
+
+    xmlDocUniquePtr pDoc = XPathHelper::parseExport(pXPathFile, m_xSFactory, "xl/worksheets/sheet1.xml");
+    CPPUNIT_ASSERT(pDoc);
+
+    assertXPath(pDoc, "/x:worksheet/x:autoFilter/x:filterColumn/x:filters", "blank", "1");
+
+    xShell->DoClose();
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(ScExportTest);
 
 CPPUNIT_PLUGIN_IMPLEMENT();
diff --git a/sc/source/filter/excel/excrecds.cxx b/sc/source/filter/excel/excrecds.cxx
index 3298d4244dff..945748ba9dca 100644
--- a/sc/source/filter/excel/excrecds.cxx
+++ b/sc/source/filter/excel/excrecds.cxx
@@ -649,9 +649,12 @@ bool XclExpAutofilter::HasCondition() const
 bool XclExpAutofilter::AddEntry( const ScQueryEntry& rEntry )
 {
     const ScQueryEntry::QueryItemsType& rItems = rEntry.GetQueryItems();
-    if (rItems.empty())
-        return true;
 
+    if (GetOutput() != EXC_OUTPUT_BINARY && rItems.empty())
+    {
+        meType = BlankValue;
+        return false;
+    }
     if (GetOutput() != EXC_OUTPUT_BINARY && rItems.size() > 1)
     {
         AddMultiValueEntry(rEntry);
@@ -817,6 +820,11 @@ void XclExpAutofilter::SaveXml( XclExpXmlStream& rStrm )
             // XML_extLst, XML_filters, XML_iconFilter, XML_top10
         }
         break;
+        case BlankValue:
+        {
+            rWorksheet->singleElement(XML_filters, XML_blank, "1");
+        }
+        break;
         case MultiValue:
         {
             rWorksheet->startElement(XML_filters);
diff --git a/sc/source/filter/inc/excrecds.hxx b/sc/source/filter/inc/excrecds.hxx
index 147808e4e758..33c24eb428a1 100644
--- a/sc/source/filter/inc/excrecds.hxx
+++ b/sc/source/filter/inc/excrecds.hxx
@@ -361,7 +361,7 @@ public:
 class XclExpAutofilter : public XclExpRecord, protected XclExpRoot
 {
 private:
-    enum FilterType { FilterCondition, MultiValue };
+    enum FilterType { FilterCondition, MultiValue, BlankValue };
     FilterType              meType;
     sal_uInt16              nCol;
     sal_uInt16              nFlags;