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

(1 則留言) (2 個反應) (1 位負責人)C# (4,257 個分叉)batch import

Area-CompilersBugFeature - Nullable Reference Typeshelp wanted

倉庫指標

星標: (20,414 顆星)
PR 合併指標: (平均合併 6天 17小時) (30 天內合併 256 個 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

貢獻者指南

研究方向: 研究Roslyn的可空流分析如何處理空檢查中的賦值，特別是在'if'語句中。追蹤控制流程圖，確保賦值後更新空狀態。
技術棧: csharp
領域: backend
議題類型: 錯誤
難度: 4
預計時間: 超過 1 週
活動狀態: 活躍
清晰度: 清晰
前置要求: C#Git
新手友善度: 30