Catch ContainerFormatError when deserialising containers

Only the deserialize() functions themselves may pass the ContainerFormatError on, because their callers will have to handle those errors anyway.

Contributes to issue CURA-5045.

cura/Settings/CuraContainerRegistry.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2017 Ultimaker B.V.
+# Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
 import os
@@ -11,6 +11,7 @@ from typing import Optional
 from PyQt5.QtWidgets import QMessageBox
 
 from UM.Decorators import override
+from UM.Settings.ContainerFormatError import ContainerFormatError
 from UM.Settings.ContainerRegistry import ContainerRegistry
 from UM.Settings.ContainerStack import ContainerStack
 from UM.Settings.InstanceContainer import InstanceContainer
@@ -25,7 +26,6 @@ from UM.Resources import Resources
 
 from . import ExtruderStack
 from . import GlobalStack
-from .ExtruderManager import ExtruderManager
 
 from cura.CuraApplication import CuraApplication
 from cura.Machines.QualityManager import getMachineDefinitionIDForQualitySearch
@@ -420,7 +420,6 @@ class CuraContainerRegistry(ContainerRegistry):
 
         Logger.log("d", "Converting ContainerStack {stack} to {type}", stack = container.getId(), type = container_type)
 
-        new_stack = None
         if container_type == "extruder_train":
             new_stack = ExtruderStack.ExtruderStack(container.getId())
         else:
@@ -706,7 +705,10 @@ class CuraContainerRegistry(ContainerRegistry):
                 instance_container = InstanceContainer(container_id)
                 with open(file_path, "r", encoding = "utf-8") as f:
                     serialized = f.read()
-                instance_container.deserialize(serialized, file_path)
+                try:
+                    instance_container.deserialize(serialized, file_path)
+                except ContainerFormatError:
+                    continue
                 self.addContainer(instance_container)
                 break