Assembly: Joint edition : Fix bug when changing offset while only one part is selected

src/Mod/Assembly/JointObject.py

@@ -282,6 +282,9 @@ class Joint:
                 self.updateJCSPlacements(joint)
                 obj1 = UtilsAssembly.getObjectInPart(joint.Object1, joint.Part1)
                 obj2 = UtilsAssembly.getObjectInPart(joint.Object2, joint.Part2)
+                if obj1 is None or obj2 is None:
+                    return
+
                 presolved = self.preSolve(
                     joint,
                     obj1,

src/Mod/Assembly/UtilsAssembly.py

@@ -241,6 +241,9 @@ def getContainingPart(full_name, selected_object, activeAssemblyOrPart=None):
 
 
 def getObjectInPart(objName, part):
+    if part is None:
+        return None
+
     if part.Name == objName:
         return part