AdisTT: user-friendly fixes on interface

src/View/BoundaryConditionsTemperature/UndoCommand.py

@@ -37,12 +37,23 @@ class SetNodeCommand(QUndoCommand):
         self._index = index
         self._old = self._bcs.get(self._index).node
         self._new = node.id if node is not None else None
+        self._previous = next(
+            (
+                bc for i, bc in enumerate(self._bcs.lst)
+                if i != self._index and bc.node == self._new
+            ),
+            None
+        )
 
     def undo(self):
         self._bcs.get(self._index).node = self._old
+        if self._previous is not None:
+            self._previous.node = self._new
 
     def redo(self):
         self._bcs.get(self._index).node = self._new
+        if self._previous is not None:
+            self._previous.node = None
 
 
 class SetNameCommand(QUndoCommand):