Auto-pairs with AltGr key cause crash

[Brixy]

Summary

Hi all,

on German keyboards ‘typographic’ quotation marks require the use of the AltGr key.

Using automatic paring in combination with the AltGr causes a helix crash.

# config.toml
[editor.auto-pairs]
'„' = '“'
'‚' = '‘'

Thank you very much!

Reproduction Steps

I tried this:

1. hx
2. Press AltGr + v

Expected behaviour: AltGr + v should produce a „; helix’s auto-pairing should extend this to „“.

Helix log

~/.cache/helix/helix.log

helix_view::editor [ERROR] Failed to initialize the LSP for `source.md` { LSP not defined }

Error message:

> thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Char index out of bounds: char index 3, Rope/RopeSlice char length 2', /host/cargo/registry/src/git.luolix.top-1ecc6299db9ec823/ropey-1.5.0/src/slice.rs:349:41
> note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Platform

Void with River WM

Terminal Emulator

Fish

Helix Version

22.08.1

[Ordoviz]

I can reproduce with the following config (any three-byte char instead of → should work):

[editor.auto-pairs]
'→' = 'a'

Typing the following causes Helix to crash:

$ RUST_BACKTRACE=1 hx
i→→
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Char index out of bounds: char index 6, Rope/RopeSlice char length 5', /home/me/.local/share/cargo/registry/src/git.luolix.top-1ecc6299db9ec823/ropey-1.5.0/src/slice.rs:349:41
stack backtrace:
   0: rust_begin_unwind
             at /rustc/1.63.0/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/1.63.0/library/core/src/panicking.rs:142:14
   2: core::result::unwrap_failed
             at /rustc/1.63.0/library/core/src/result.rs:1805:5
   3: ropey::slice::RopeSlice::char_to_byte
   4: helix_core::graphemes::nth_next_grapheme_boundary
   5: helix_core::selection::Selection::ensure_invariants
   6: helix_view::document::Document::apply_impl
   7: helix_view::document::Document::apply
   8: helix_term::commands::insert::insert_char
   9: helix_term::ui::editor::EditorView::insert_mode
  10: <helix_term::ui::editor::EditorView as helix_term::compositor::Component>::handle_event
  11: helix_term::compositor::Compositor::handle_event
  12: helix_term::application::Application::handle_terminal_events
  13: helix_term::application::Application::event_loop_until_idle::{{closure}}
  14: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
  15: std::thread::local::LocalKey<T>::with
  16: tokio::park::thread::CachedParkThread::block_on
  17: tokio::runtime::scheduler::multi_thread::MultiThread::block_on
  18: tokio::runtime::Runtime::block_on
  19: hx::main

The first → moves the cursor onto the next line, the second → moves the cursor past the buffer, causing the crash.

[dead10ck]

Thanks for the report, I was able to reproduce. I'll look into this when I get a chance.

[dead10ck]

I've identified the issue, should have a PR up either tonight or tomorrow.

[Omnikar]

I've identified the issue, should have a PR up either tonight or tomorrow.

Any update?

[dead10ck]

I've identified the issue, should have a PR up either tonight or tomorrow.

Any update?

Yes, sorry, it's pretty close now. I took this opportunity to migrate the auto pairs tests to the integration framework, but I encountered a couple of bugs in the helper functions that delayed it a bit. But I should have a PR ready in a day or two.

[dead10ck]

PR submitted: #4024