fix(compiler): preserve union case names on unknown-carrier collisions - #4106
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chaokunyang merged 2 commits intoOct 5, 2026
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…member Every generated C# union declares an Unknown(UnknownCase) member for the unknown-case fallback. A schema union case named "unknown" produced a second 'sealed partial record Unknown' in the same union, which fails to compile (CS0102). Rename such a case record to UnknownValue; case identity is the ForyCase number, so the rename does not affect wire behavior. Claude-Session: https://claude.ai/code/session_01YcPbRyTJYmU8t6mkGCbnUf
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What does this PR do?
An IDL union case named
unknowncollides with the automatically generated unknown-case carrier in C#, Kotlin, Scala, Rust, and Swift. Renaming the schema case toUnknownValuealso collides when the schema declaresunknown_value.Preserve schema case names and rename only the generated carrier: use
Unknown_on collision in C#, Kotlin, Scala, and Rust, orunknown_in Swift. If the alternate name is also occupied, fail generation. The source generators identify the carrier by its annotation or attribute, preserving its structural and uniqueness requirements. Case IDs, defaults, and wire encoding remain unchanged.Validation