ofz#3760 Divide-by-zero

Change-Id: I951d5f167effe8cb856e28afec890218df698fde
Reviewed-on: https://gerrit.libreoffice.org/43760Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sd/source/core/sdpage.cxx

@@ -3064,7 +3064,7 @@ void SdPage::CalculateHandoutAreas( SdDrawDocument& rModel, AutoLayout eLayout,
         aPartArea.Height() = ((aArea.Height() - ((nRowCnt-1) * nGapH) ) / nRowCnt);
 
         SdrPage* pFirstPage = rModel.GetMasterSdPage(0, PageKind::Standard);
-        if ( pFirstPage )
+        if (pFirstPage && pFirstPage->GetWidth() && pFirstPage->GetHeight())
         {
             // scale actual size into handout rect
             double fScale = (double)aPartArea.Width() / (double)pFirstPage->GetWidth();