Part/Toponaming: align TopoShape::findSubShapesWithSharedVertex() to LS3

* added test for issue #15539

Signed-off-by: CalligaroV <vincenzo.calligaro@gmail.com>

src/Mod/Part/TestPartApp.py

@@ -468,6 +468,64 @@ class PartTestRuledSurface(unittest.TestCase):
         self.assertEqual(len(same1), 2)
         self.assertEqual(len(same2), 2)
 
+    def testRuledSurfaceFromTwoObjectsWithSharedVertexs(self):
+        """Test reproducing issue #15539"""
+
+        # Arrange
+        line = Part.makeLine(FreeCAD.Vector(0, 0, 50), FreeCAD.Vector(0, -50, 0))
+        line1 = Part.makeLine(FreeCAD.Vector(0, 0, 50), FreeCAD.Vector(50, 0, 0))
+        line2 = Part.makeLine(FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(0, -50, 0))
+        line3 = Part.makeLine(FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(50, 0, 0))
+        fea = self.Doc.addObject("Part::Feature")
+        fea1 = self.Doc.addObject("Part::Feature")
+        fea2 = self.Doc.addObject("Part::Feature")
+        fea3 = self.Doc.addObject("Part::Feature")
+        fea.Shape = line
+        fea1.Shape = line1
+        fea2.Shape = line2
+        fea3.Shape = line3
+
+        # Defining all the surfaces generated by 2 lines with one common vertex
+        ruled = self.Doc.addObject("Part::RuledSurface")
+        ruled.Curve1 = fea
+        ruled.Curve2 = fea1
+
+        ruled1 = self.Doc.addObject("Part::RuledSurface")
+        ruled1.Curve1 = fea1
+        ruled1.Curve2 = fea3
+
+        ruled2 = self.Doc.addObject("Part::RuledSurface")
+        ruled2.Curve1 = fea2
+        ruled2.Curve2 = fea3
+
+        ruled3 = self.Doc.addObject("Part::RuledSurface")
+        ruled3.Curve1 = fea
+        ruled3.Curve2 = fea2
+
+        # Act
+        self.Doc.recompute()
+
+        # Assert
+        same00 = getCoincidentVertexes(fea.Shape.Vertexes, ruled.Shape.Vertexes)
+        same03 = getCoincidentVertexes(fea.Shape.Vertexes, ruled3.Shape.Vertexes)
+        same10 = getCoincidentVertexes(fea1.Shape.Vertexes, ruled.Shape.Vertexes)
+        same11 = getCoincidentVertexes(fea1.Shape.Vertexes, ruled1.Shape.Vertexes)
+        same22 = getCoincidentVertexes(fea2.Shape.Vertexes, ruled2.Shape.Vertexes)
+        same23 = getCoincidentVertexes(fea2.Shape.Vertexes, ruled3.Shape.Vertexes)
+        same31 = getCoincidentVertexes(fea3.Shape.Vertexes, ruled1.Shape.Vertexes)
+        same32 = getCoincidentVertexes(fea3.Shape.Vertexes, ruled2.Shape.Vertexes)
+
+        # BRepFill::Face() seems creating faces with 4 vertexes
+        # Therefore, in this case, every face shares 3 vertexes (1 counted twice as coincident) with the lines that generate that face
+        self.assertEqual(len(same00), 3)
+        self.assertEqual(len(same03), 3)
+        self.assertEqual(len(same10), 3)
+        self.assertEqual(len(same11), 3)
+        self.assertEqual(len(same22), 3)
+        self.assertEqual(len(same23), 3)
+        self.assertEqual(len(same31), 3)
+        self.assertEqual(len(same32), 3)
+
     def testRuledSurfaceFromOneObject(self):
         sketch = self.Doc.addObject('Sketcher::SketchObject', 'Sketch')
         sketch.Placement = FreeCAD.Placement(FreeCAD.Vector(0.000000, 0.000000, 0.000000), App.Rotation(0.707107, 0.000000, 0.000000, 0.707107))