thread 'main' panicked at helix-core/src/graphemes.rs:173:5: assertion failed: char_idx <= slice.len_chars()

[nik-rev]

Summary

Helix panics when trying to insert newliens

Reproduction Steps

On the latest release

> RUST_BACKTRARCE=1 cargo run -- lol.sql
    Finished dev [unoptimized + debuginfo] target(s) in 0.11s
     Running `target/debug/hx lol.sql`
thread 'main' panicked at helix-core/src/graphemes.rs:173:5:
assertion failed: char_idx <= slice.len_chars()
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

With the following file, cursor at the beginning:

id 1,Item 1,cost 1,location 1
id 2,Item 2,cost 2,location 2
id 10,Item 10,cost 10,location 10

• Press % to select full file
• Place cursor on each digit with s\d
• Go into insert mode i then add a newline <enter>
• Panic happens here.

Backtrace

thread 'main' panicked at helix-core/src/graphemes.rs:173:5:
assertion failed: char_idx <= slice.len_chars()
stack backtrace:
   0: rust_begin_unwind
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:645:5
   1: core::panicking::panic_fmt
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:72:14
   2: core::panicking::panic
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:144:5
   3: helix_core::graphemes::nth_next_grapheme_boundary
             at ./helix-core/src/graphemes.rs:173:5
   4: helix_core::graphemes::next_grapheme_boundary
             at ./helix-core/src/graphemes.rs:252:5
   5: helix_core::graphemes::ensure_grapheme_boundary_next
             at ./helix-core/src/graphemes.rs:270:9
   6: helix_core::selection::Range::grapheme_aligned
             at ./helix-core/src/selection.rs:288:17
   7: helix_core::selection::Selection::ensure_invariants::{{closure}}
             at ./helix-core/src/selection.rs:664:28
   8: helix_core::selection::Selection::transform
             at ./helix-core/src/selection.rs:642:22
   9: helix_core::selection::Selection::ensure_invariants
             at ./helix-core/src/selection.rs:664:9
  10: helix_view::document::Document::apply_impl
             at ./helix-view/src/document.rs:1441:17
  11: helix_view::document::Document::apply_inner
             at ./helix-view/src/document.rs:1484:23
  12: helix_view::document::Document::apply
             at ./helix-view/src/document.rs:1496:9
  13: helix_term::commands::insert::insert_newline
             at ./helix-term/src/commands.rs:4110:9
  14: helix_term::commands::MappableCommand::execute
             at ./helix-term/src/commands.rs:261:41
  15: helix_term::ui::editor::EditorView::handle_keymap_event::{{closure}}
             at ./helix-term/src/ui/editor.rs:893:13
  16: helix_term::ui::editor::EditorView::handle_keymap_event
             at ./helix-term/src/ui/editor.rs:919:17
  17: helix_term::ui::editor::EditorView::insert_mode
             at ./helix-term/src/ui/editor.rs:933:34
  18: <helix_term::ui::editor::EditorView as helix_term::compositor::Component>::handle_event
             at ./helix-term/src/ui/editor.rs:1466:33
  19: helix_term::compositor::Compositor::handle_event
             at ./helix-term/src/compositor.rs:152:19
  20: helix_term::application::Application::handle_terminal_events::{{closure}}
             at ./helix-term/src/application.rs:668:22
  21: helix_term::application::Application::event_loop_until_idle::{{closure}}
             at ./helix-term/src/application.rs:341:56
  22: helix_term::application::Application::event_loop::{{closure}}
             at ./helix-term/src/application.rs:315:58
  23: helix_term::application::Application::run::{{closure}}
             at ./helix-term/src/application.rs:1230:39
  24: hx::main_impl::{{closure}}
             at ./helix-term/src/main.rs:157:54
  25: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/future/future.rs:124:9
  26: tokio::runtime::park::CachedParkThread::block_on::{{closure}}
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/park.rs:281:63
  27: tokio::runtime::coop::with_budget
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/coop.rs:107:5
  28: tokio::runtime::coop::budget
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/coop.rs:73:5
  29: tokio::runtime::park::CachedParkThread::block_on
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/park.rs:281:31
  30: tokio::runtime::context::blocking::BlockingRegionGuard::block_on
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/context/blocking.rs:66:9
  31: tokio::runtime::scheduler::multi_thread::MultiThread::block_on::{{closure}}
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/scheduler/multi_thread/mod.rs:87:13
  32: tokio::runtime::context::runtime::enter_runtime
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/context/runtime.rs:65:16
  33: tokio::runtime::scheduler::multi_thread::MultiThread::block_on
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/scheduler/multi_thread/mod.rs:86:9
  34: tokio::runtime::runtime::Runtime::block_on_inner
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/runtime.rs:370:45
  35: tokio::runtime::runtime::Runtime::block_on
             at /home/e/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/runtime/runtime.rs:340:13
  36: hx::main_impl
             at ./helix-term/src/main.rs:159:5
  37: hx::main
             at ./helix-term/src/main.rs:37:21
  38: core::ops::function::FnOnce::call_once
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Helix log

empty

Platform

Linux

Terminal Emulator

wezterm 8e9cf91

Installation Method

Built from source

Helix Version

helix 25.1 (6c9619d)

[freelon]

This seems to be a regression. I see the same panic with 25.1 but not with 24.7 (using konsole).

[RoloEdits]

A bisect points to 1e6fe00

[nik-rev]

In this line:

id 10,Item 10,cost 10,location 10

Observations:

If you place a cursor at each digit except the last 0, then enter a newline, the panic won't happen

If you do have a cursor at the last 0, then the panic happens

If you have a cursor on the 4th, 5th, 6th, 7th and the last 8th digit then the panic won't happen

If you have a cursor on the 3rd digit as well as all the above, the panic happens.

[nik-rev]

I finally figured it out: #12510