tdf#99680 modified clipping for PDF export

If clipping is requested, but no clipping region is defined,
clipping is ignored.

Change-Id: I793c1de1f4f6b0203727c0ff6aa8adecc43ad413
Reviewed-on: https://gerrit.libreoffice.org/38021Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

vcl/source/gdi/pdfwriter_impl.cxx

@@ -12063,12 +12063,13 @@ void PDFWriterImpl::updateGraphicsState(Mode const mode)
                 getReferenceDevice()->SetMapMode( rNewState.m_aMapMode );
                 m_aCurrentPDFState.m_aMapMode = rNewState.m_aMapMode;
 
-                aLine.append( "q " );
-                if( rNewState.m_aClipRegion.count() )
+                if ( rNewState.m_aClipRegion.count() )
+                {
+                    aLine.append( "q " );
                     m_aPages.back().appendPolyPolygon( rNewState.m_aClipRegion, aLine );
-                else
-                    aLine.append( "0 0 m h " ); // NULL clip, i.e. nothing visible
-                aLine.append( "W* n\n" );
+                    aLine.append( "W* n\n" );
+                }
+
                 rNewState.m_aMapMode = aNewMapMode;
                 getReferenceDevice()->SetMapMode( rNewState.m_aMapMode );
                 m_aCurrentPDFState.m_aMapMode = rNewState.m_aMapMode;