Mod: Show regressions in shape colouring

This PR demonstrates the known regressions of the recently merged material branch:
* Changing the transparency after setting color per face will reset them
* The result of boolean operations or compound doesn't inherit the colour of its input objects
* If colour is set per face to a boolean operaton object then saving and restoring the file causes weird rendering behaviour
  because material binding is set to PER_PART but only a single colour is defined
* If a shape inside a part container has set colour per face then saving and restoring as STEP file causes weird rendering
behaviour for the same reason
* Shape binder or datum objects don't show the correct default shape colour

src/Mod/Part/parttests/ColorPerFaceTest.py

@@ -8,6 +8,7 @@ import Part
 import os
 import tempfile
 import unittest
+from BOPTools import BOPFeatures
 from pivy import coin
 
 class ColorPerFaceTest(unittest.TestCase):
@@ -84,3 +85,123 @@ class ColorPerFaceTest(unittest.TestCase):
 
         mat = paths.get(2).getTail()
         self.assertEqual(mat.diffuseColor.getNum(), 6)
+
+    def testTransparency(self):
+        """
+        If color per face is set then changing the transparency must not revert it
+        """
+        box = self.doc.addObject("Part::Box","Box")
+        self.doc.recompute()
+
+        box.ViewObject.DiffuseColor = [(1.,0.,0.,0.),
+                                       (1.,0.,0.,0.),
+                                       (1.,0.,0.,0.),
+                                       (1.,0.,0.,0.),
+                                       (1.,1.,0.,0.),
+                                       (1.,1.,0.,0.)]
+
+        box.ViewObject.Transparency = 35
+        self.assertEqual(box.ViewObject.Transparency, 35)
+
+        sa = coin.SoSearchAction()
+        sa.setType(coin.SoMaterialBinding.getClassTypeId())
+        # We need an easier way to access nodes of a display mode
+        sa.setInterest(coin.SoSearchAction.ALL)
+        sa.apply(box.ViewObject.RootNode)
+        paths = sa.getPaths()
+
+        bind = paths.get(2).getTail()
+        self.assertEqual(bind.value.getValue(), bind.PER_PART)
+
+        sa = coin.SoSearchAction()
+        sa.setType(coin.SoMaterial.getClassTypeId())
+        # We need an easier way to access nodes of a display mode
+        sa.setInterest(coin.SoSearchAction.ALL)
+        sa.apply(box.ViewObject.RootNode)
+        paths = sa.getPaths()
+
+        mat = paths.get(2).getTail()
+        self.assertEqual(mat.diffuseColor.getNum(), 6)
+
+    def testMultiFuse(self):
+        """
+        Both input objects are red. So, it's expected that the output object is red, too.
+        """
+        box = self.doc.addObject("Part::Box","Box")
+        cyl = self.doc.addObject("Part::Cylinder","Cylinder")
+        box.ViewObject.ShapeColor = (1.,0.,0.,0.)
+        cyl.ViewObject.ShapeColor = (1.,0.,0.,0.)
+        self.doc.recompute()
+
+        bp = BOPFeatures.BOPFeatures(self.doc)
+        fuse = bp.make_multi_fuse([box.Name, cyl.Name])
+        self.assertEqual(fuse.TypeId, "Part::MultiFuse")
+        self.doc.recompute()
+
+        sa = coin.SoSearchAction()
+        sa.setType(coin.SoMaterialBinding.getClassTypeId())
+        # We need an easier way to access nodes of a display mode
+        sa.setInterest(coin.SoSearchAction.ALL)
+        sa.apply(fuse.ViewObject.RootNode)
+        paths = sa.getPaths()
+
+        bind = paths.get(2).getTail()
+        self.assertEqual(bind.value.getValue(), bind.PER_PART)
+
+        sa = coin.SoSearchAction()
+        sa.setType(coin.SoMaterial.getClassTypeId())
+        # We need an easier way to access nodes of a display mode
+        sa.setInterest(coin.SoSearchAction.ALL)
+        sa.apply(fuse.ViewObject.RootNode)
+        paths = sa.getPaths()
+
+        mat = paths.get(2).getTail()
+        self.assertEqual(mat.diffuseColor.getNum(), 11)
+
+        self.assertEqual(len(fuse.Shape.Faces), 11)
+        self.assertEqual(len(fuse.ViewObject.DiffuseColor), 11)
+        self.assertEqual(fuse.ViewObject.DiffuseColor[0], (1.,0.,0.,0.))
+
+    def testMultiFuseSaveRestore(self):
+        box = self.doc.addObject("Part::Box","Box")
+        cyl = self.doc.addObject("Part::Cylinder","Cylinder")
+        box.ViewObject.ShapeColor = (1.,0.,0.,0.)
+        cyl.ViewObject.ShapeColor = (1.,0.,0.,0.)
+        self.doc.recompute()
+
+        bp = BOPFeatures.BOPFeatures(self.doc)
+        fuse = bp.make_multi_fuse([box.Name, cyl.Name])
+        self.assertEqual(fuse.TypeId, "Part::MultiFuse")
+        self.doc.recompute()
+
+        fuse.ViewObject.DiffuseColor = [(1.,0.,0.,0.)] * 11
+
+        self.doc.saveAs(self.fileName)
+        App.closeDocument(self.doc.Name)
+
+        self.doc = App.openDocument(self.fileName)
+
+        fuse = self.doc.ActiveObject
+        self.assertEqual(len(fuse.Shape.Faces), 11)
+        self.assertEqual(len(fuse.ViewObject.DiffuseColor), 11)
+        self.assertEqual(fuse.ViewObject.DiffuseColor[0], (1.,0.,0.,0.))
+
+        sa = coin.SoSearchAction()
+        sa.setType(coin.SoMaterialBinding.getClassTypeId())
+        # We need an easier way to access nodes of a display mode
+        sa.setInterest(coin.SoSearchAction.ALL)
+        sa.apply(fuse.ViewObject.RootNode)
+        paths = sa.getPaths()
+
+        bind = paths.get(2).getTail()
+        self.assertEqual(bind.value.getValue(), bind.PER_PART)
+
+        sa = coin.SoSearchAction()
+        sa.setType(coin.SoMaterial.getClassTypeId())
+        # We need an easier way to access nodes of a display mode
+        sa.setInterest(coin.SoSearchAction.ALL)
+        sa.apply(fuse.ViewObject.RootNode)
+        paths = sa.getPaths()
+
+        mat = paths.get(2).getTail()
+        self.assertEqual(mat.diffuseColor.getNum(), 11)