Export data layout field to xlsx correctly.

Excel uses a field index of -2 to indicate a data layout field.

Change-Id: I6b18c0bcff439eb4425ef0b0d0b841633dc81dd7

sc/source/filter/excel/xepivotxml.cxx

@@ -395,6 +395,10 @@ void XclExpXmlPivotTables::SavePivotTableXml( XclExpXmlStream& rStrm, const ScDP
         const ScDPSaveDimension& rDim = rDims[i];
 
         long nPos = -1; // position in cache
+        if (rDim.IsDataLayout())
+            nPos = -2; // Excel uses an index of -2 to indicate a data layout field.
+        else
+        {
             OUString aSrcName = ScDPUtil::getSourceDimensionName(rDim.GetName());
             NameToIdMapType::iterator it = aNameToIdMap.find(aSrcName);
             if (it != aNameToIdMap.end())
@@ -405,6 +409,7 @@ void XclExpXmlPivotTables::SavePivotTableXml( XclExpXmlStream& rStrm, const ScDP
 
             if (!aCachedDims[nPos])
                 continue;
+        }
 
         sheet::DataPilotFieldOrientation eOrient =
             static_cast<sheet::DataPilotFieldOrientation>(rDim.GetOrientation());