AD0001 - NullReferenceException when running CA2246

[RobSiklos]

Analyzer package

Microsoft.CodeAnalysis.FxCopAnalyzers

Package Version

v2.9.5

Diagnostic ID

CA2246

Repro steps

Analyze the following code:

public static class Class1
{
    public static void Foo()
    {
        var u = new System.UriBuilder();
        u.Host = u.Path = string.Empty;
    }
}

Expected behavior

No warning or error.

Actual behavior

Analyzer 'Microsoft.CodeQuality.Analyzers.QualityGuidelines.AssigningSymbolAndItsMemberInSameStatement' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'

Analyzer 'Microsoft.CodeQuality.Analyzers.QualityGuidelines.AssigningSymbolAndItsMemberInSameStatement' threw the following exception:
'Exception occurred with following context:
Compilation: RoslynAnalyzersFalsePositives
IOperation: SimpleAssignment
SyntaxTree: D:\src\Rob\RoslynAnalyzersFalsePositives\RoslynAnalyzersFalsePositives\CA2246.cs
SyntaxNode: u.Host = u.Path = string.Empty [AssignmentExpressionSyntax]@[193..223) (7,12)-(7,42)

System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.CodeQuality.Analyzers.QualityGuidelines.AssigningSymbolAndItsMemberInSameStatement.<>c.b__8_0(ILocalReferenceOperation a, ILocalReferenceOperation b)
at Microsoft.CodeQuality.Analyzers.QualityGuidelines.AssigningSymbolAndItsMemberInSameStatement.AnalyzeAssignmentToMember[T](ISimpleAssignmentOperation assignmentOperation, T instance, Func3 equalityComparer) at Microsoft.CodeQuality.Analyzers.QualityGuidelines.AssigningSymbolAndItsMemberInSameStatement.AnalyzeAssignment(OperationAnalysisContext context) at Microsoft.CodeAnalysis.Diagnostics.AnalyzerExecutor.<>c.<ExecuteOperationAction>b__54_0(ValueTuple2 data)
at Microsoft.CodeAnalysis.Diagnostics.AnalyzerExecutor.ExecuteAndCatchIfThrows_NoLock[TArg](DiagnosticAnalyzer analyzer, Action1 analyze, TArg argument, Nullable1 info)

[mavasani]

Thanks for the prompt bug report @RobSiklos. I will work on a fix and point you a myget package with the fix. Based on number of folks that hit this, we may have to release a 2.9.6-beta1 or 2.9.6 for this fix.

[mavasani]

@RobSiklos @abelykh0 can you please try https://dotnet.myget.org/feed/roslyn-analyzers/package/nuget/Microsoft.CodeAnalysis.FxCopAnalyzers/2.9.6-beta1.19502.2+ce473561?

[RobSiklos]

Confirmed fixed in 2.9.6-beta1.19502.2+ce473561. Thanks @mavasani !

[mavasani]

FYI: We got large number of customer reports for this AD0001. So, we have just published 2.9.6 with this fix: https://github.com/dotnet/roslyn-analyzers/releases/tag/v2.9.6

Thanks everyone for helping find and fix this issue promptly.

[adamralph]

I'm using 2.10.0 and I'm still having this problem.

[adamralph]

Sorry, it's a different error message. I guess I'll raise a new issue...

[adamralph]

#1803 (comment)