Merge pull request #787 from Ultimaker/exception_handling_fixes

Minor Exception handling Fixes

cura/CrashHandler.py

@@ -5,17 +5,33 @@ import webbrowser
 
 from PyQt5.QtCore import QT_VERSION_STR, PYQT_VERSION_STR, QCoreApplication
 from PyQt5.QtWidgets import QDialog, QDialogButtonBox, QVBoxLayout, QLabel, QTextEdit
+
+from UM.Logger import Logger
 from UM.i18n import i18nCatalog
 catalog = i18nCatalog("cura")
 
+# List of exceptions that should be considered "fatal" and abort the program.
+# These are primarily some exception types that we simply cannot really recover from
+# (MemoryError and SystemError) and exceptions that indicate grave errors in the
+# code that cause the Python interpreter to fail (SyntaxError, ImportError). 
+fatal_exception_types = [
+    MemoryError,
+    SyntaxError,
+    ImportError,
+    SystemError,
+]
+
 def show(exception_type, value, tb):
     debug_mode = False
     if QCoreApplication.instance():
         debug_mode = QCoreApplication.instance().getCommandLineOption("debug-mode", False)
 
-    traceback.print_exception(exception_type, value, tb)
+    Logger.log("c", "An uncaught exception has occurred!")
+    for line in traceback.format_exception(exception_type, value, tb):
+        for part in line.rstrip("\n").split("\n"):
+            Logger.log("c", part)
 
-    if not debug_mode:
+    if not debug_mode and exception_type not in fatal_exception_types:
         return
 
     application = QCoreApplication.instance()
@@ -29,7 +45,7 @@ def show(exception_type, value, tb):
 
     label = QLabel(dialog)
     layout.addWidget(label)
-    label.setText(catalog.i18nc("@label", "<p>An uncaught exception has occurred!</p><p>Please use the information below to post a bug report at <a href=\"http://github.com/Ultimaker/Cura/issues\">http://github.com/Ultimaker/Cura/issues</a></p>"))
+    label.setText(catalog.i18nc("@label", "<p>A fatal exception has occurred that we could not recover from!</p><p>Please use the information below to post a bug report at <a href=\"http://github.com/Ultimaker/Cura/issues\">http://github.com/Ultimaker/Cura/issues</a></p>"))
 
     textarea = QTextEdit(dialog)
     layout.addWidget(textarea)

cura/MachineManagerModel.py

@@ -51,8 +51,7 @@ class MachineManagerModel(QObject):
 
         if active_machine_id != "":
             # An active machine was saved, so restore it.
-            self.setActiveMachine(active_machine_id)
-            pass
+            Application.getInstance().callLater(self.setActiveMachine, active_machine_id)
 
     globalContainerChanged = pyqtSignal()
     activeMaterialChanged = pyqtSignal()