LSP: Extra newlines are inserted when requesting `"crlf"` in a document with pre-existing unix line endings

• Open a Unix line ending R file
• Set line-ending = "crlf" in an air.toml
• Save using the LSP

https://github.com/user-attachments/assets/09ed3a96-35e9-436b-9e3f-ec3fd5a9bb93

I think this line is relevant?
https://github.com/posit-dev/air/blob/dac87ff76d4b0b4f2ad0d48c3d6a7386a04c54ca/crates/lsp/src/documents.rs#L64

I'm not 100% sure what is going on:

• Client opens unix document. Document::new() sets LineIndex's endings to LineEnding::Lf
• Formatting occurs on save. Formatter uses air.toml option and generates a formatted string output with Crlf endings (\r\n)
• replace_all_edit() is called using the original line index and its original stored options, i.e. endings of Lf! A bunch of Indels are generated, with insertions of \r because that is the only difference. It does seem like we keep the \r all the way through this function and send it back to the frontend?

Start in crates/lsp/src/documents.rs at Document::new and replace_all_edit(), then reproduce the reported save flow with a Unix-ending R file and line-ending = "crlf". Done means saving through the LSP no longer inserts extra newlines while applying the requested CRLF endings.