fdo#75975 crash while saving the DOCX file containing charts

1. Open DOCX file containing Charts
2. Save this file into DOCX format.
3. LO crashed while saving/exporting to DOCX format.

Conflicts:
	chart2/qa/extras/chart2export.cxx

Change-Id: I14d4f2c214ce3513b4bd14831771d72498e4486d

chart2/qa/extras/chart2export.cxx

@@ -50,6 +50,7 @@ public:
     void testPieChartDataLabels();
     void testSeriesIdxOrder();
     void testErrorBarDataRangeODS();
+    void testChartCrash();
 
     CPPUNIT_TEST_SUITE(Chart2ExportTest);
     CPPUNIT_TEST(test);
@@ -72,6 +73,7 @@ public:
     CPPUNIT_TEST(testPieChartDataLabels);
     CPPUNIT_TEST(testSeriesIdxOrder);
     CPPUNIT_TEST(testErrorBarDataRangeODS);
+    CPPUNIT_TEST(testChartCrash);
     CPPUNIT_TEST_SUITE_END();
 
 protected:
@@ -653,6 +655,13 @@ void Chart2ExportTest::testErrorBarDataRangeODS()
     CPPUNIT_ASSERT_EQUAL(OUString("$Sheet1.$C$1:$C$3"), aNegRange);
 }
 
+void Chart2ExportTest::testChartCrash()
+{
+    load("/chart2/qa/extras/data/docx/", "FDO75975.docx");
+    xmlDocPtr pXmlDoc = parseExport("word/charts/chart", "Office Open XML Text");
+    CPPUNIT_ASSERT(pXmlDoc);
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(Chart2ExportTest);
 
 CPPUNIT_PLUGIN_IMPLEMENT();

oox/source/export/chartexport.cxx

@@ -2307,7 +2307,7 @@ void ChartExport::_exportAxis(
     {
         pFS->startElement( FSNS( XML_c, XML_minorGridlines ),
             FSEND );
-        exportShapeProps( xMajorGrid );
+        exportShapeProps( xMinorGrid );
         pFS->endElement( FSNS( XML_c, XML_minorGridlines ) );
     }