Nullability no longer honors null check when it is also an assignment · dotnet/roslyn

(1 条评论) (2 个反应) (1 位负责人)C# (4,257 个派生)batch import

Area-CompilersBugFeature - Nullable Reference Typeshelp wanted

仓库指标

星标: (20,414 个星标)
PR 合并指标: (平均合并 6天 17小时) (30 天内合并 256 个 PR)

描述

Version Used: master (19 May 2020)

Steps to Reproduce:

Do assignment of the null check expression inside an if statement.

Repro code: https://sharplab.io/#v2:EYLgtghgzgLgpgJwDQBMQGoA+BiAdgVwBtCJhC4ACOXU8gWACgABAJgEZGmBmC1igYQoBvRhTG8eTACwUAsgAoAlMNHi1qtWIBiAex0UAZhQC8FXHADuFXTqUBuDZsdrgewhQCWUAHJFCDhk1xDyN5L19iE0MAOgAFBB0AB0QYAE8KAEJTAmJFZ3ERQKDNJjYATnkDOITkhDTogBUdABkdC0QlRQDiigBfR36GQc5JFms9RkK1bl42AAYAfgp4pJT0oQoAczgYOwooHb3B3qA===

Expected Behavior: Object was already checked for null, nullability should no longer warn "Possible null reference".

Actual Behavior: Nullability still warn "Possible null reference" regardless of the previous null check.

cc @jaredpar @cston @jcouv

贡献者指南

研究方向: 研究Roslyn的可空流分析如何处理空检查中的赋值，特别是在'if'语句中。跟踪控制流图，确保赋值后更新空状态。
技术栈: csharp
领域: backend
议题类型: 缺陷
难度: 4
预计时间: 超过 1 周
活动状态: 活跃
清晰度: 清晰
前置要求: C#Git
新手友好度: 30