Prevent crash due to NullReferenceException in interactive window component #4589
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| _eval.WriteError(FixNewLines(e.Data)); | ||
| try { | ||
| _eval.WriteError(FixNewLines(e.Data)); | ||
| } catch (Exception ex) when (!ex.IsCriticalException()) { |
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See the stack and links I've put in #4513
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Ok, can we check Dispatcher.HasShutdownStarted in when condition?
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How? With Dispatcher.CurrentDispatcher.HasShutdownStarted? Docs say that never returns null, that one is created if there isn't one. Will it have the same values as the dispatcher object in the interactive window:
private Dispatcher Dispatcher => ((FrameworkElement)_uiOnly.TextView).Dispatcher; // Always safe to access the dispatcher.
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// Always safe to access the dispatcher.
Well, that's actually not true: https://referencesource.microsoft.com/#WindowsBase/Base/System/Windows/Freezable.cs,887
We should be able to use _eval.CurrentWindow.TextView.VisualElement.Dispatcher == null
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I just saw the exception while I was debugging, I was able verify that _eval.CurrentWindow.TextView.VisualElement.Dispatcher.HasShutdownStarted==true (and _eval.CurrentWindow.TextView.VisualElement.Dispatcher.hasShutdownFinished==true)
so I'll catch if shutdown started or dispatcher is null.
…e window sometimes throws.
| @@ -290,7 +291,8 @@ Process process | |||
| if (!AppendPreConnectionOutput(e)) { | |||
| try { | |||
| _eval.WriteOutput(FixNewLines(e.Data)); | |||
| } catch (Exception ex) when (!ex.IsCriticalException()) { | |||
| } catch (Exception ex) when (!ex.IsCriticalException() && | |||
| (_eval.CurrentWindow.TextView.VisualElement.Dispatcher?.HasShutdownStarted ?? true)) { | |||
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Let's extract it into separate method.
| try { | ||
| _eval.WriteError(FixNewLines(e.Data)); | ||
| } catch (Exception ex) when (!ex.IsCriticalException() && | ||
| (_eval.CurrentWindow.TextView.VisualElement.Dispatcher?.HasShutdownStarted ?? true)) { |
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Let's extract it into method
Fix #4513
Adding the same type of protection we already had in
ProcessExitedhandler to theStdErrReceivedandStdOutReceivedhandlers.