Bullets: Use relative size when it's supported

In Writer it might cause a problem to use relative
size with text based numberings.

Change-Id: Id19b5e45f0f932d1b69028f343daad7dec34ae23
Reviewed-on: https://gerrit.libreoffice.org/66811
Tested-by: Jenkins
Reviewed-by: Tamás Zolnai <tamas.zolnai@collabora.com>

cui/source/tabpages/numpages.cxx

@@ -2438,10 +2438,13 @@ void SvxNumberingPreview::Paint(vcl::RenderContext& rRenderContext, const ::tool
                 {
                     vcl::Font aFont(aStdFont);
                     Size aTmpSize(aStdFont.GetFontSize());
-                    aTmpSize.setWidth( aTmpSize.Width() * ( rFmt.GetBulletRelSize()) );
-                    aTmpSize.setWidth( aTmpSize.Width() / 100 ) ;
-                    aTmpSize.setHeight( aTmpSize.Height() * ( rFmt.GetBulletRelSize()) );
-                    aTmpSize.setHeight( aTmpSize.Height() / 100 ) ;
+                    if(pActNum->IsFeatureSupported(SvxNumRuleFlags::BULLET_REL_SIZE))
+                    {
+                        aTmpSize.setWidth( aTmpSize.Width() * ( rFmt.GetBulletRelSize()) );
+                        aTmpSize.setWidth( aTmpSize.Width() / 100 ) ;
+                        aTmpSize.setHeight( aTmpSize.Height() * ( rFmt.GetBulletRelSize()) );
+                        aTmpSize.setHeight( aTmpSize.Height() / 100 ) ;
+                    }
                     if(!aTmpSize.Height())
                         aTmpSize.setHeight( 1 );
                     aFont.SetFontSize(aTmpSize);