C#: Fix parsing of nullable type constraints#7077
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knutwannheden merged 1 commit intomainfrom Mar 20, 2026
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`ParseConstraintExpression` used `Visit()` (Roslyn's visitor dispatch) to parse type constraints, but `NullableTypeSyntax` has no dedicated visitor override — only `VisitType()` handles it. This caused `Visit()` to return null, which propagated into the `JContainer<Expression>` and triggered a `NullReferenceException` during RPC serialization.
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Summary
NullReferenceExceptionwhen parsing nullable type constraints likewhere T : IComparable<T>?ParseConstraintExpressionusedVisit()(Roslyn's visitor dispatch) which returned null forNullableTypeSyntaxsince there's no dedicated override — switched toVisitType()which handles itNullOrOutOfRangeInternal<T>haswhere T : IComparable<T>?Test plan
struct)ClassDeclarationTestspass