Path.Area: fix self intersect wire issue

Self intersected wire may cause a loop, and BRepBuilderAPI_MakeWire may
mistakenly consider the wire to be closed. And this makes
BrepTools_WireExplorer unhappy and cause it to skip edges.  We now use
ShapeAnalysis_FreeBounds to connect edges to wires.

src/Mod/Path/App/Area.cpp

@@ -81,6 +81,7 @@
 #include <ShapeFix_ShapeTolerance.hxx>
 #include <ShapeExtend_WireData.hxx>
 #include <ShapeFix_Wire.hxx>
+#include <ShapeAnalysis_FreeBounds.hxx>
 
 #include <Base/Exception.h>
 #include <Base/Tools.h>
@@ -1610,7 +1611,7 @@ void Area::build() {
             WireJoiner joiner;
             gp_Trsf trsf(myTrsf.Inverted());
             for(const auto &c : myArea->m_curves) {
-                TopoDS_Wire wire = toShape(c,&trsf);
+                auto wire = toShape(c,&trsf);
                 if(!wire.IsNull())
                     joiner.add(wire);
             }
@@ -2045,8 +2046,9 @@ static inline bool IsLeft(const gp_Pnt &a, const gp_Pnt &b, const gp_Pnt &c) {
     return ((b.X() - a.X())*(c.Y() - a.Y()) - (b.Y() - a.Y())*(c.X() - a.X())) > 0;
 }
 
-TopoDS_Wire Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
-    BRepBuilderAPI_MakeWire mkWire;
+TopoDS_Shape Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
+    Handle(TopTools_HSequenceOfShape) hEdges = new TopTools_HSequenceOfShape();
+    Handle(TopTools_HSequenceOfShape) hWires = new TopTools_HSequenceOfShape();
 
     CCurve cReversed;
     if(reorient) {
@@ -2061,6 +2063,7 @@ TopoDS_Wire Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
     }
     const CCurve &c = reorient?cReversed:_c;
 
+    TopoDS_Shape shape;
     gp_Pnt pstart,pt;
     bool first = true;
     for(const CVertex &v : c.m_vertices){
@@ -2074,7 +2077,7 @@ TopoDS_Wire Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
             continue;
         if(v.m_type == 0) {
             auto edge = BRepBuilderAPI_MakeEdge(pt,pnext).Edge();
-            mkWire.Add(edge);
+            hEdges->Append(edge);
         } else {
             gp_Pnt center(v.m_c.x,v.m_c.y,0);
             double r = center.Distance(pt);
@@ -2102,7 +2105,7 @@ TopoDS_Wire Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
                 gp_Ax2 axis(center, gp_Dir(0,0,v.m_type));
                 try {
                     auto edge = BRepBuilderAPI_MakeEdge(gp_Circ(axis,r),pt,pnext).Edge();
-                    mkWire.Add(edge);
+                    hEdges->Append(edge);
                     break;
                 } catch(Standard_Failure &e) {
                     if(!fix_arc) {
@@ -2117,11 +2120,8 @@ TopoDS_Wire Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
         }
         pt = pnext;
     }
-    if(!mkWire.IsDone()) {
-        AREA_WARN("failed to make wire " << mkWire.Error());
-        return TopoDS_Wire();
-    }
 
+#if 0
     if(c.IsClosed() && !BRep_Tool::IsClosed(mkWire.Wire())){
         // This should never happen after changing libarea's
         // Point::tolerance to be the same as Precision::Confusion().
@@ -2134,10 +2134,26 @@ TopoDS_Wire Area::toShape(const CCurve &_c, const gp_Trsf *trsf, int reorient) {
             AREA_XYZ(p2)<<endl<<AREA_XYZ(pt)<<endl<<AREA_XYZ(pstart));
         mkWire.Add(BRepBuilderAPI_MakeEdge(pt,pstart).Edge());
     }
+#endif
+
+    ShapeAnalysis_FreeBounds::ConnectEdgesToWires(
+            hEdges, Precision::Confusion(), Standard_False, hWires);
+    if(!hWires->Length())
+        return shape;
+    if(hWires->Length()==1)
+        shape = hWires->Value(1);
+    else {
+        BRep_Builder builder;
+        TopoDS_Compound compound;
+        builder.MakeCompound(compound);
+        for(int i=1;i<=hWires->Length();++i)
+            builder.Add(compound,hWires->Value(i));
+        shape = compound;
+    }
+    
     if(trsf)
-        return TopoDS::Wire(mkWire.Wire().Moved(TopLoc_Location(*trsf)));
-    else
-        return mkWire.Wire();
+        shape.Move(TopLoc_Location(*trsf));
+    return shape;
 }
 
 TopoDS_Shape Area::toShape(const CArea &area, bool fill, const gp_Trsf *trsf, int reorient) {
@@ -2146,7 +2162,7 @@ TopoDS_Shape Area::toShape(const CArea &area, bool fill, const gp_Trsf *trsf, in
     builder.MakeCompound(compound);
 
     for(const CCurve &c : area.m_curves) {
-        const TopoDS_Wire &wire = toShape(c,trsf,reorient);
+        const auto &wire = toShape(c,trsf,reorient);
         if(!wire.IsNull())
             builder.Add(compound,wire);
     }

src/Mod/Path/App/Area.h

@@ -329,7 +329,7 @@ public:
      * \arg \c trsf: optional transform matrix to transform the shape back into
      * its original position.
      * */
-    static TopoDS_Wire toShape(const CCurve &curve, const gp_Trsf *trsf=NULL, int reorient=0);
+    static TopoDS_Shape toShape(const CCurve &curve, const gp_Trsf *trsf=NULL, int reorient=0);
 
     /** Check if two OCC shape is coplanar */
     static bool isCoplanar(const TopoDS_Shape &s1, const TopoDS_Shape &s2);