NullReferenceException is thrown when caret touches `orderby` in LINQ expression

[jhinder]

Version Used: VS 17.12.4

Steps to Reproduce:
Place the caret on the orderby token.

_ = from n in Enumerable.Empty<int>()
    orderby n descending
    select n;

Expected Behavior: No exception.

Actual Behavior:
Gold bar "Feature 'Document highlights' is currently unavailable due to an internal error" with the following stacktrace:

StreamJsonRpc.RemoteInvocationException: Object reference not set to an instance of an object.
   at StreamJsonRpc.JsonRpc.<InvokeCoreAsync>d__156`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.Remote.BrokeredServiceConnection`1.<TryInvokeAsync>d__20`1.MoveNext()
RPC server exception:
System.NullReferenceException: Object reference not set to an instance of an object.
      at Microsoft.CodeAnalysis.ImmutableArrayExtensions.WhereAsArrayImpl[T,TArg](ImmutableArray`1 array, Func`2 predicateWithoutArg, Func`3 predicateWithArg, TArg arg)
      at Microsoft.CodeAnalysis.Shared.Extensions.SemanticModelExtensions.GetSemanticInfo(SemanticModel semanticModel, SyntaxToken token, SolutionServices services, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.FindSymbols.SymbolFinder.GetSemanticInfoAtPositionAsync(SemanticModel semanticModel, Int32 position, SolutionServices services, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.FindSymbols.SymbolFinder.FindSymbolAtPositionAsync(SemanticModel semanticModel, Int32 position, SolutionServices services, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.DocumentHighlighting.AbstractDocumentHighlightsService.GetDocumentHighlightsInCurrentProcessAsync(Document document, Int32 position, IImmutableSet`1 documentsToSearch, HighlightingOptions options, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.DocumentHighlighting.AbstractDocumentHighlightsService.GetDocumentHighlightsAsync(Document document, Int32 position, IImmutableSet`1 documentsToSearch, HighlightingOptions options, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.Remote.RemoteDocumentHighlightsService.<>c__DisplayClass2_0.<<GetDocumentHighlightsAsync>b__0>d.MoveNext()
   --- End of stack trace from previous location ---
      at Microsoft.CodeAnalysis.Remote.RemoteWorkspace.<>c__DisplayClass7_0`1.<<RunWithSolutionAsync>g__ProcessSolutionAsync|1>d.MoveNext()
   --- End of stack trace from previous location ---
      at Microsoft.CodeAnalysis.Remote.RemoteWorkspace.RunWithSolutionAsync[T](AssetProvider assetProvider, Checksum solutionChecksum, Boolean updatePrimaryBranch, Func`2 implementation, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.Remote.RemoteWorkspace.RunWithSolutionAsync[T](AssetProvider assetProvider, Checksum solutionChecksum, Boolean updatePrimaryBranch, Func`2 implementation, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.Remote.BrokeredServiceBase.RunWithSolutionAsync[T](Checksum solutionChecksum, Func`2 implementation, CancellationToken cancellationToken)
      at Microsoft.CodeAnalysis.Remote.BrokeredServiceBase.RunServiceImplAsync[T](Func`2 implementation, CancellationToken cancellationToken)

[CyrusNajmabadi]

I believe this was fixed. So you get this on latest preview?

[jhinder]

Seems to be fixed, cannot reproduce with VS 17.13.3.