Fix protobuf oneof default values#3147
Open
xiaozhikang0916 wants to merge 2 commits intoKotlin:devfrom
Open
Conversation
Override `shouldEncodeElementDefault` in `OneOfElementEncoder` to always return true. This ensures oneof fields are encoded even when they contain default values (e.g., 0 for int, "" for string, or empty message). According to protobuf oneof semantics, the selected case must always be identifiable. Without this fix, encoding a oneof with default values would produce an empty output, making it impossible to distinguish which variant was selected during decoding. Fixes Kotlin#3144
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Override
shouldEncodeElementDefaultinOneOfElementEncoderto always return true. This ensures oneof fields are encoded even when they contain default values.According to protobuf oneof semantics, the selected case must always be identifiable. So a tag with field number is always needed for one of field.
Fixes #3144
And I found that code sample in the issue shows some misusing of default values in proto messages. So I add an extra section in docs for it.