NullReferenceException from inlineRenameSession.InitializeOpenBuffers while binding pattern

[tmat]

at Microsoft.CodeAnalysis.CSharp.ConversionsBase.HasImplicitEnumerationConversion(BoundExpression source, TypeSymbol destination)
at Microsoft.CodeAnalysis.CSharp.ConversionsBase.ClassifyImplicitBuiltInConversionFromExpression(BoundExpression sourceExpression, TypeSymbol source, TypeSymbol destination, HashSet`1& useSiteDiagnostics)
at Microsoft.CodeAnalysis.CSharp.ConversionsBase.ClassifyImplicitConversionFromExpression(BoundExpression sourceExpression, TypeSymbol destination, HashSet`1& useSiteDiagnostics)
at Microsoft.CodeAnalysis.CSharp.Binder.GenerateConversionForAssignment(TypeSymbol targetType, BoundExpression expression, DiagnosticBag diagnostics, Boolean isDefaultParameter, RefKind refKind)
at Microsoft.CodeAnalysis.CSharp.Binder.ConvertPatternExpression(TypeSymbol inputType, CSharpSyntaxNode node, BoundExpression expression, ConstantValue& constantValue, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.Binder.BindConstantPattern(CSharpSyntaxNode node, BoundExpression operand, TypeSymbol operandType, ExpressionSyntax patternExpression, Boolean hasErrors, DiagnosticBag diagnostics, Boolean& wasExpression, Boolean wasSwitchCase)
at Microsoft.CodeAnalysis.CSharp.Binder.BindPattern(PatternSyntax node, BoundExpression operand, TypeSymbol operandType, Boolean hasErrors, DiagnosticBag diagnostics, Boolean wasSwitchCase)
at Microsoft.CodeAnalysis.CSharp.Binder.BindIsPatternExpression(IsPatternExpressionSyntax node, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.Binder.BindExpressionInternal(ExpressionSyntax node, DiagnosticBag diagnostics, Boolean invoked, Boolean indexed)
at Microsoft.CodeAnalysis.CSharp.Binder.BindExpression(ExpressionSyntax node, DiagnosticBag diagnostics, Boolean invoked, Boolean indexed)
at Microsoft.CodeAnalysis.CSharp.Binder.BindExpressionStatement(CSharpSyntaxNode node, ExpressionSyntax syntax, Boolean allowsAnyExpression, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.Binder.BindExpressionStatement(ExpressionStatementSyntax node, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.Binder.BindStatement(StatementSyntax node, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.MemberSemanticModel.IncrementalBinder.BindStatement(StatementSyntax node, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.CSharpSemanticModel.Bind(Binder binder, CSharpSyntaxNode node, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.MethodBodySemanticModel.Bind(Binder binder, CSharpSyntaxNode node, DiagnosticBag diagnostics)
at Microsoft.CodeAnalysis.CSharp.MemberSemanticModel.GetBoundNodes(CSharpSyntaxNode node)
at Microsoft.CodeAnalysis.CSharp.MemberSemanticModel.GetLowerBoundNode(CSharpSyntaxNode node)
at Microsoft.CodeAnalysis.CSharp.MemberSemanticModel.GetBoundNodes(CSharpSyntaxNode node, CSharpSyntaxNode& bindableNode, BoundNode& lowestBoundNode, BoundNode& highestBoundNode, BoundNode& boundParent)
at Microsoft.CodeAnalysis.CSharp.MemberSemanticModel.GetSymbolInfoWorker(CSharpSyntaxNode node, SymbolInfoOptions options, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.CSharp.SyntaxTreeSemanticModel.GetSymbolInfoWorker(CSharpSyntaxNode node, SymbolInfoOptions options, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.CSharp.CSharpSemanticModel.GetSymbolInfo(ExpressionSyntax expression, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.CSharp.CSharpExtensions.GetSymbolInfo(SemanticModel semanticModel, ExpressionSyntax expression, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.CSharp.Classification.Classifiers.NameSyntaxClassifier.ClassifyTypeSyntax(NameSyntax name, SemanticModel semanticModel, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.CSharp.Classification.Classifiers.NameSyntaxClassifier.ClassifyNode(SyntaxNode syntax, SemanticModel semanticModel, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.Classification.AbstractClassificationService.Worker.ClassifyNode(SyntaxNode syntax)
at Microsoft.CodeAnalysis.Classification.AbstractClassificationService.Worker.ProcessNodes()
at Microsoft.CodeAnalysis.Classification.AbstractClassificationService.Worker.Classify(Workspace workspace, SemanticModel semanticModel, TextSpan textSpan, List`1 list, Func`2 getNodeClassifiers, Func`2 getTokenClassifiers, CancellationToken cancellationToken)
at Microsoft.CodeAnalysis.Classification.AbstractClassificationService.d__5.MoveNext()

[OmarTawfik]

@tmat do we have a repro for this exception?

[tmat]

Unfortunately I do not :( It happened while dogfooding. Not sure why i haven't saved a crash dump.

[OmarTawfik]

@tmat @jaredpar no repro so far on my side. Are we OK moving it to RTM?

[tmat]

Sure, if you don't see what can be wrong juts from the stack trace then let's close until we have a repro.

[OmarTawfik]

Alright. Spent time today trying possible scenarios, no repro. Please re-open if you do.