From a8b123fe177d8cd7f5a610a0a50c16c9f64069bd Mon Sep 17 00:00:00 2001 From: Gokul Soumya Date: Fri, 22 Jul 2022 21:53:08 +0530 Subject: [PATCH] Fix byte index error in signature help highlighting The language server sends a char offset range within the signature help label text to highlight as the current parameter, but helix uses byte offset ranges for rendering highlights. This was brought up in the [review of the original signature help PR][1], but the ranges were being highlighted correctly, and there were no out of bound or indexing panics. Turns out rust-analyzer was [incorrectly sending byte offsets] instead of char offsets and this made it seem like all was well and good with offsets in helix during initial testing. [1]: https://github.com/helix-editor/helix/pull/1755#discussion_r906715371 [2]: https://github.com/rust-lang/rust-analyzer/pull/12272 --- helix-term/src/commands/lsp.rs | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/helix-term/src/commands/lsp.rs b/helix-term/src/commands/lsp.rs index 1785a50c..38507e4d 100644 --- a/helix-term/src/commands/lsp.rs +++ b/helix-term/src/commands/lsp.rs @@ -904,7 +904,12 @@ pub fn signature_help_impl(cx: &mut Context, invoked: SignatureHelpInvoked) { Some((start, start + string.len())) } lsp::ParameterLabel::LabelOffsets([start, end]) => { - Some((*start as usize, *end as usize)) + // LS sends offsets based on utf-16 based string representation + // but highlighting in helix is done using byte offset. + use helix_core::str_utils::char_to_byte_idx; + let from = char_to_byte_idx(&signature.label, *start as usize); + let to = char_to_byte_idx(&signature.label, *end as usize); + Some((from, to)) } } };