C#: Harden cs/useless-cast-to-self with respect to unknown types. - #22393
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michaelnebel merged 2 commits intoAug 20, 2026
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Pull request overview
Prevents false positives from unknown C# types, especially in buildless databases.
Changes:
- Excludes
UnknownTypefrom redundant self-cast results. - Documents the behavior change.
Show a summary per file
| File | Description |
|---|---|
csharp/ql/src/Language Abuse/UselessCastToSelf.ql |
Filters casts involving unknown types. |
csharp/ql/src/change-notes/2026-08-20-harden-useless-cast-to-self.md |
Adds the fix note. |
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- Files reviewed: 2/2 changed files
- Comments generated: 1
- Review effort level: Balanced
| type = cast.getTargetType() and | ||
| type = e.getType() and | ||
| not type instanceof NullType and | ||
| not type instanceof UnknownType and |
hvitved
approved these changes
Aug 20, 2026
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Especially for
build-mode: noneexpressions can more easily be of unknown type (and the same goes for types used in casts). Such cases should not be reported by the querycs/useless-cast-to-self.This change removes around 7k results across the repos in the DCA suite.