Only access css::drawing::PointSequence when not empty

Had to adapt EscherPropertyContainer::GetPolyPolygon due
to it using conversions from UNO API drawing::PointSequence
to old tools::polygon, containing unsafe memory accesses.
It is not useful to fix that, use new tooling instead.

Before correctly testing nCount for zero in b2dpolygontools.cxx
when you look closely always a point was added - a random
one due to accessing random memory.
This is corrected, so in test case for "tdf104115.docx"
a PolyPolygon with two polys is used, the first being
empty (had one point due to the error mentioned above).
When having no points, CreatePolygonProperties in escherex.cxx
does badly calculate and alloc the pSegmentBuf array used
to write to doc formats (in the test case - 20 bytes alloced,
22 written). This did not happen before due to having
always a point due to the error before - argh!
Corrected that and hopefully this will work now.

To be on the safe side and to not need to redefine that whole
CreatePolygonProperties I will turn back that little change
and better sort-out empty polygons inside GetPolyPolygon
alrteady. That should bring us back to the original state,
at the same time avoiding that CreatePolygonProperties has
to handle empty Polygons at all.
That stuff urgently needs cleanup - I took a look and thought
about using std::vector<sal_uInt8> so no wrong alloc or write
too much could happen, but that nTotalBezPoints needs to be
pre-calculated because it gets itself written to that
buffers...

Change-Id: Iefc885928f5bb29bceaf36c2a1555346bb21fd26
Reviewed-on: https://gerrit.libreoffice.org/56927
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>

basegfx/source/polygon/b2dpolygontools.cxx

@@ -3285,6 +3285,9 @@ namespace basegfx
 
             // prepare new polygon
             B2DPolygon aRetval;
+
+            if(0 != nCount)
+            {
                 const css::awt::Point* pPointSequence = rPointSequenceSource.getConstArray();
                 const css::drawing::PolygonFlags* pFlagSequence = rFlagSequenceSource.getConstArray();
 
@@ -3369,6 +3372,7 @@ namespace basegfx
                 // #i72807# API import uses old line start/end-equal definition for closed,
                 // so we need to correct this to closed state here
                 checkClosed(aRetval);
+            }
 
             return aRetval;
         }

filter/source/msfilter/escherex.cxx

@@ -93,6 +93,8 @@
 #include <vcl/virdev.hxx>
 #include <rtl/crc.h>
 #include <rtl/strbuf.hxx>
+#include <basegfx/polygon/b2dpolypolygontools.hxx>
+#include <basegfx/polygon/b2dpolygontools.hxx>
 #include <memory>
 
 using namespace css;
@@ -1735,120 +1737,36 @@ tools::PolyPolygon EscherPropertyContainer::GetPolyPolygon( const uno::Reference
     return aRetPolyPoly;
 }
 
+// adapting to basegfx::B2DPolyPolygon now, has no sense to do corrections in the
+// old tools::PolyPolygon creation code. Convert to that at return time
 tools::PolyPolygon EscherPropertyContainer::GetPolyPolygon( const uno::Any& rAny )
 {
-    bool bNoError = true;
+    basegfx::B2DPolyPolygon aRetval;
 
-    tools::Polygon aPolygon;
-    tools::PolyPolygon aPolyPolygon;
-
-    if ( rAny.getValueType() == cppu::UnoType<drawing::PolyPolygonBezierCoords>::get())
-    {
-        auto pSourcePolyPolygon = o3tl::doAccess<drawing::PolyPolygonBezierCoords>(rAny);
-        sal_uInt16 nOuterSequenceCount = static_cast<sal_uInt16>(pSourcePolyPolygon->Coordinates.getLength());
-
-        // get pointer of inner sequences
-        drawing::PointSequence const * pOuterSequence = pSourcePolyPolygon->Coordinates.getConstArray();
-        drawing::FlagSequence const *  pOuterFlags = pSourcePolyPolygon->Flags.getConstArray();
-
-        bNoError = pOuterSequence && pOuterFlags;
-        if ( bNoError )
-        {
-            sal_uInt16  a, b, nInnerSequenceCount;
-            awt::Point const * pArray;
-
-            // this will be a polygon set
-            for ( a = 0; a < nOuterSequenceCount; a++ )
-            {
-                drawing::PointSequence const * pInnerSequence = pOuterSequence++;
-                drawing::FlagSequence const *  pInnerFlags = pOuterFlags++;
-
-                bNoError = pInnerSequence && pInnerFlags;
-                if  ( bNoError )
-                {
-                    // get pointer to arrays
-                    pArray = pInnerSequence->getConstArray();
-                    drawing::PolygonFlags const * pFlags = pInnerFlags->getConstArray();
-
-                    if ( pArray && pFlags )
+    if(auto pBCC = o3tl::tryAccess<drawing::PolyPolygonBezierCoords>(rAny))
     {
-                        nInnerSequenceCount = static_cast<sal_uInt16>(pInnerSequence->getLength());
-                        aPolygon = tools::Polygon( nInnerSequenceCount );
-                        for( b = 0; b < nInnerSequenceCount; b++)
-                        {
-                            drawing::PolygonFlags ePolyFlags = *pFlags++;
-                            awt::Point aPoint( *(pArray++) );
-                            aPolygon[ b ] = Point( aPoint.X, aPoint.Y );
-                            aPolygon.SetFlags( b, static_cast<PolyFlags>(ePolyFlags) );
-
-                            if ( ePolyFlags == drawing::PolygonFlags_CONTROL )
-                                continue;
-                        }
-                        aPolyPolygon.Insert( aPolygon );
-                    }
-                }
-            }
+        aRetval = basegfx::utils::UnoPolyPolygonBezierCoordsToB2DPolyPolygon(*pBCC);
     }
+    else if(auto pCC = o3tl::tryAccess<drawing::PointSequenceSequence>(rAny))
+    {
+        aRetval = basegfx::utils::UnoPointSequenceSequenceToB2DPolyPolygon(*pCC);
     }
-    else if ( auto pSourcePolyPolygon = o3tl::tryAccess<drawing::PointSequenceSequence>(rAny) )
+    else if(auto pC = o3tl::tryAccess<drawing::PointSequence>(rAny))
     {
-        sal_uInt16 nOuterSequenceCount = static_cast<sal_uInt16>(pSourcePolyPolygon->getLength());
+        aRetval.append(basegfx::utils::UnoPointSequenceToB2DPolygon(*pC));
+    }
 
-        // get pointer to inner sequences
-        drawing::PointSequence const * pOuterSequence = pSourcePolyPolygon->getConstArray();
-        bNoError = pOuterSequence != nullptr;
-        if ( bNoError )
-        {
-            sal_uInt16 a, b, nInnerSequenceCount;
+    basegfx::B2DPolyPolygon aRetval2;
 
-            // this will be a polygon set
-            for( a = 0; a < nOuterSequenceCount; a++ )
-            {
-                drawing::PointSequence const * pInnerSequence = pOuterSequence++;
-                bNoError = pInnerSequence != nullptr;
-                if ( bNoError )
-                {
-                    // get pointer to arrays
-                    awt::Point const * pArray =
-                          pInnerSequence->getConstArray();
-                    if ( pArray != nullptr )
+    for(sal_uInt32 a(0); a < aRetval.count(); a++)
     {
-                        nInnerSequenceCount = static_cast<sal_uInt16>(pInnerSequence->getLength());
-                        aPolygon = tools::Polygon( nInnerSequenceCount );
-                        for( b = 0; b < nInnerSequenceCount; b++)
+        if(0 != aRetval.getB2DPolygon(a).count())
         {
-                            aPolygon[ b ] = Point( pArray->X, pArray->Y );
-                            pArray++;
-                        }
-                        aPolyPolygon.Insert( aPolygon );
+            aRetval2.append(aRetval.getB2DPolygon(a));
         }
     }
-            }
-        }
-    }
-    else if ( auto pInnerSequence = o3tl::tryAccess<drawing::PointSequence>(rAny) )
-    {
-        bNoError = pInnerSequence != nullptr;
-        if ( bNoError )
-        {
-            sal_uInt16 a, nInnerSequenceCount;
 
-            // get pointer to arrays
-            awt::Point const * pArray = pInnerSequence->getConstArray();
-            if ( pArray != nullptr )
-            {
-                nInnerSequenceCount = static_cast<sal_uInt16>(pInnerSequence->getLength());
-                aPolygon = tools::Polygon( nInnerSequenceCount );
-                for( a = 0; a < nInnerSequenceCount; a++)
-                {
-                    aPolygon[ a ] = Point( pArray->X, pArray->Y );
-                    pArray++;
-                }
-                aPolyPolygon.Insert( aPolygon );
-            }
-        }
-    }
-    return aPolyPolygon;
+    return tools::PolyPolygon(aRetval2);
 }
 
 bool EscherPropertyContainer::CreatePolygonProperties(