Crash when opening file - SyntaxEditor for WPF Forum

Posted 7 months ago by Tobias Lingemann - Software Devolpment Engineer, Vector Informatik GmbH

Version: 22.1.1

Platform: .NET 4.8

Environment: Windows 11 (64-bit)

Hello,

a customer reported a sporadic crash that happens when the previously opened documents are restored.

The crash happens in EditorView.OnPointerHoverTimerTick(). I suppose there a scenarios where the services collection can be null.

System.NullReferenceException: Object reference not set to an instance of an object.
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.wtu()
   at ActiproSoftware.Internal.qTr.PMR()
   at ActiproSoftware.Internal.qTr.xMW(xkM  )
   at ActiproSoftware.Internal.qTr.FML(xkM  )
   at ActiproSoftware.Internal.qTr.xkM.Destroy()
   at ActiproSoftware.Text.Tagging.Implementation.DelimiterHighlightTagger.t1L(Object  , EventArgs  )
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.rtU()
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.Vta()
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.OnLostFocus(RoutedEventArgs e)
   at System.Windows.UIElement.IsFocused_Changed(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.ClearValueCommon(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata)
   at System.Windows.DependencyObject.ClearValue(DependencyPropertyKey key)
   at System.Windows.Input.FocusManager.OnFocusedElementChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   at System.Windows.Input.FocusManager.SetFocusedElement(DependencyObject element, IInputElement value)
   at System.Windows.Input.FocusManager.GetFocusedElement(DependencyObject element, Boolean validate)
   at System.Windows.FrameworkElement.OnPreviewGotKeyboardFocus(Object sender, KeyboardFocusChangedEventArgs e)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.KeyboardDevice.TryChangeFocus(DependencyObject newFocus, IKeyboardInputProvider keyboardInputProvider, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   at System.Windows.Input.KeyboardDevice.Focus(DependencyObject focus, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   at System.Windows.Input.KeyboardDevice.Focus(IInputElement element)
   at System.Windows.Input.KeyboardDevice.CheckForDisconnectedFocus()
   at System.Windows.Input.KeyboardDevice.PreNotifyInput(Object sender, NotifyInputEventArgs e)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndKeyboardInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawKeyboardActions actions, Int32 scanCode, Boolean isExtendedKey, Boolean isSystemKey, Int32 virtualKey)
   at System.Windows.Interop.HwndKeyboardInputProvider.PossiblyDeactivate(IntPtr hwndFocus)
   at System.Windows.Interop.HwndKeyboardInputProvider.FilterMessage(IntPtr hwnd, WindowMessage message, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at ActiproSoftware.Internal.qTr.xMW(xkM  )
   at ActiproSoftware.Internal.qTr.FML(xkM  )
   at ActiproSoftware.Internal.qTr.xkM.Destroy()
   at ActiproSoftware.Text.Tagging.Implementation.DelimiterHighlightTagger.t1L(Object  , EventArgs  )
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.rtU()
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.Vta()
   at ActiproSoftware.Windows.Controls.SyntaxEditor.Primitives.EditorView.OnLostFocus(RoutedEventArgs e)
   at System.Windows.UIElement.IsFocused_Changed(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.ClearValueCommon(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata)
   at System.Windows.DependencyObject.ClearValue(DependencyPropertyKey key)
   at System.Windows.Input.FocusManager.OnFocusedElementChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   at System.Windows.Input.FocusManager.SetFocusedElement(DependencyObject element, IInputElement value)
   at System.Windows.Input.FocusManager.GetFocusedElement(DependencyObject element, Boolean validate)
   at System.Windows.FrameworkElement.OnPreviewGotKeyboardFocus(Object sender, KeyboardFocusChangedEventArgs e)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.KeyboardDevice.TryChangeFocus(DependencyObject newFocus, IKeyboardInputProvider keyboardInputProvider, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   at System.Windows.Input.KeyboardDevice.Focus(DependencyObject focus, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   at System.Windows.Input.KeyboardDevice.Focus(IInputElement element)
   at System.Windows.Input.KeyboardDevice.CheckForDisconnectedFocus()
   at System.Windows.Input.KeyboardDevice.PreNotifyInput(Object sender, NotifyInputEventArgs e)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndKeyboardInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawKeyboardActions actions, Int32 scanCode, Boolean isExtendedKey, Boolean isSystemKey, Int32 virtualKey)
   at System.Windows.Interop.HwndKeyboardInputProvider.PossiblyDeactivate(IntPtr hwndFocus)
   at System.Windows.Interop.HwndKeyboardInputProvider.FilterMessage(IntPtr hwnd, WindowMessage message, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at System.Windows.Forms.UnsafeNativeMethods.SetFocus(HandleRef hWnd)
   at System.Windows.Forms.UnsafeNativeMethods.SetFocus(HandleRef hWnd)
   at System.Windows.Forms.Control.FocusInternal()
   at System.Windows.Forms.Control.Focus()
   at System.Windows.Forms.Integration.WinFormsAdapter.FocusNext(TraversalRequest request)
   at Vector.ITE.WpfCommon.Interop.RestoringFocusWindowsFormsHost.TabInto(TraversalRequest request)
   at System.Windows.Input.KeyboardNavigation.Navigate(DependencyObject currentElement, TraversalRequest request, ModifierKeys modifierKeys, DependencyObject firstElement, Boolean fromProcessInputTabKey)
   at System.Windows.FrameworkElement.MoveFocus(TraversalRequest request)
   at System.Windows.Controls.TabItem.OnPreviewGotKeyboardFocus(KeyboardFocusChangedEventArgs e)
   at ActiproSoftware.Windows.Controls.Docking.AdvancedTabItem.OnPreviewGotKeyboardFocus(KeyboardFocusChangedEventArgs e)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.KeyboardDevice.TryChangeFocus(DependencyObject newFocus, IKeyboardInputProvider keyboardInputProvider, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   at System.Windows.Input.KeyboardDevice.Focus(DependencyObject focus, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   at System.Windows.Input.KeyboardDevice.Focus(IInputElement element)
   at System.Windows.UIElement.Focus()
   at System.Windows.Controls.TabItem.SetFocus()
   at System.Windows.Controls.TabControl.OnSelectionChanged(SelectionChangedEventArgs e)
   at ActiproSoftware.Windows.Controls.Docking.AdvancedTabControl.OnSelectionChanged(SelectionChangedEventArgs e)
   at ActiproSoftware.Windows.Controls.Docking.Primitives.TabbedMdiContainerTabControl.OnSelectionChanged(SelectionChangedEventArgs e)
   at System.Windows.Controls.Primitives.Selector.SelectionChanger.End()
   at System.Windows.Controls.Primitives.Selector.SelectionChanger.SelectJustThisItem(ItemInfo info, Boolean assumeInItemsCollection)
   at System.Windows.Controls.Primitives.Selector.OnSelectedItemChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
   at System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)
   at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)
   at MS.Internal.Data.PropertyPathWorker.UpdateSourceValueState(Int32 k, ICollectionView collectionView, Object newValue, Boolean isASubPropertyChange)
   at MS.Internal.Data.PropertyPathWorker.OnDependencyPropertyChanged(DependencyObject d, DependencyProperty dp, Boolean isASubPropertyChange)
   at System.Windows.Data.BindingExpression.HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
   at System.Windows.Data.BindingExpressionBase.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
   at System.Windows.Data.BindingExpression.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
   at System.Windows.DependentList.InvalidateDependents(DependencyObject source, DependencyPropertyChangedEventArgs sourceArgs)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   at ActiproSoftware.Windows.Controls.Docking.TabbedMdiHost.ActiproSoftware.Windows.Controls.Docking.Models.IMdiHost.BringToFront(DockingWindow window)
   at ActiproSoftware.Internal.AR.fQs(DockingWindow  , Boolean  )
   at ActiproSoftware.Internal.AR.Activate(DockingWindow window, Boolean focus)
   at ActiproSoftware.Windows.Controls.Docking.DockingWindow.Activate(Boolean focus)
   at Vector.ITE.ViewManagement.ViewManagementServiceProvider.ShowViewInFrameWindow(IViewRepresentation viewRepresentation, Boolean forceFocus)

I only have the sources for v22.1.5, so I am not sure if there have been any changes since v22.1.1.

Best regards, Tobias Lingemann.

Comments (2)

Answer - Posted 7 months ago by Actipro Software Support - Cleveland, OH, USA

Hi Tobias,

Is this something you have been able to reproduce or is the stack trace from the customer the only information currently available?

I've tried to reproduce this issue with our C# language add-on and modifications to our SDI Code Editor sample, but haven't encountered any issues. When you say "previously opened documents are restored", I assume that to mean an IEditorDocument instance is being cached when an editor is closed and then, when reopened, the SyntaxEditor.Document property is assigned the cached IEditorDocument instance.

In our sample, I simulated this by creating a cache of IEditorDocument instances based on the full path of the file that was opened. I then modified the "File > Open" command to attempt to restore a document from cache (by setting the SE.Document property) if the same file was reopened. I was able to switch between several cached documents without issue.

If you're able to reproduce this, please provide steps. If I misunderstood the scenario of "previously opened documents are restored", please provide some additional context.

Either way, we've added additional null checks everywhere language services are retrieved to guard against this scenario in the future. This update will be in the next maintenance release. Please note that we just had a release last week so it might be a while before that gets published.

Actipro Software Support

Posted 7 months ago by Tobias Lingemann - Software Devolpment Engineer, Vector Informatik GmbH

Hi,

I was not able to reproduce the issue yet, so the stack trace from the customer is the only information available right now.

He said the issue occurs sporadically and from the log I can count at least three occurrences. And no, I don’t mean that the IEditorDocument instances are cached. When the project is closed, we remember the file paths of the open documents and open them again when the project is loaded again. So its just that multiple documents are loaded directly after each other.

Thank you for your help.

Best regards, Tobias Lingemann.

The latest build of this product (v24.1.2) was released 6 days ago, which was after the last post in this thread.

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