Part: fixes #6584: Pocket becomes a pad when next object ofter a polar pattern

src/Mod/Part/App/modelRefine.cpp

@@ -60,6 +60,7 @@
 # include <BRepBndLib.hxx>
 # include <ShapeAnalysis_Edge.hxx>
 # include <ShapeAnalysis_Curve.hxx>
+# include <ShapeAnalysis_Shell.hxx>
 # include <BRepAdaptor_Curve.hxx>
 # include <TColgp_SequenceOfPnt.hxx>
 # include <GeomAPI_ProjectPointOnSurf.hxx>
@@ -1042,6 +1043,7 @@ bool FaceUniter::process()
     typeObjects.push_back(&getBSplineObject());
     //add more face types.
 
+    bool checkFinalShell = false;
     ModelRefine::FaceTypeSplitter splitter;
     splitter.addShell(workShell);
     std::vector<FaceTypedBase *>::iterator typeIt;
@@ -1072,7 +1074,7 @@ bool FaceUniter::process()
                     // the created face should have the same orientation as the input faces
                     const FaceVectorType& faces = adjacencySplitter.getGroup(adjacentIndex);
                     if (!faces.empty() && newFace.Orientation() != faces[0].Orientation()) {
-                        newFace.Orientation(faces[0].Orientation());
+                        checkFinalShell = true;
                     }
                     facesToSew.push_back(newFace);
                     if (facesToRemove.capacity() <= facesToRemove.size() + adjacencySplitter.getGroup(adjacentIndex).size())
@@ -1154,6 +1156,19 @@ bool FaceUniter::process()
             faceFixer.Perform();
         }
         workShell = TopoDS::Shell(edgeFuse.Shape());
+
+        // A difference of orientation between original and fused faces was previously detected
+        if (checkFinalShell) {
+            ShapeAnalysis_Shell check;
+            check.LoadShells(workShell);
+            if (!check.HasFreeEdges()) {
+                // the shell is a solid, make sure that volume is positive
+                GProp_GProps props;
+                BRepGProp::VolumeProperties(workShell, props);
+                if (props.Mass() < 0)
+                    workShell = TopoDS::Shell(workShell.Reversed());
+            }
+        }
         // update the list of modifications
         TopTools_DataMapOfShapeShape faceMap;
         edgeFuse.Faces(faceMap);