Command suggestions sometimes panic in self.is_char_boundary(n)

[ReagentX]

Summary

Using tab to complete/cycle through completion options sometimes crashes with the following message:

thread 'main' panicked at 'assertion failed: self.is_char_boundary(n)', /rustc/9d1b2106e23b1abd32fce1f17267604a5102f57a/library/alloc/src/string.rs:1718:29

Reproduction Steps

I tried this:

1. hx
2. type :theme
3. press tab to start autocomplete
4. Space to select theme
5. tab again to select from the theme list

I expected this to happen:

The selection moves through the theme list

Instead, this happened:

thread 'main' panicked at 'assertion failed: self.is_char_boundary(n)', /rustc/9d1b2106e23b1abd32fce1f17267604a5102f57a/library/alloc/src/string.rs:1718:29

Helix log

~/.cache/helix/helix.log is empty

Platform

macOS

Terminal Emulator

alacritty 0.10.1 (2844606)

Helix Version

helix 22.03 (d4e45fd)

[sudormrfbin]

Duplicate of #1246, but it's still not reproducible in my machine :/

[archseer]

Can you get us a full backtrace by setting the env RUST_BACKTRACE=1?

[ReagentX]

I tried that, but there was no additional output.

[archseer]

I tried that, but there was no additional output.

Did you export the env var? What exactly did you run

[archseer]

Feels like the range returned by completions isn't aligned to a char which then causes replace_range to panic

helix/helix-term/src/ui/prompt.rs

Line 311 in d37369c

let (range, item) = &self.completion[index];

[archseer]

Could also be because the completion isn't recalculated when you press tab, but the completions are all calculated from what the original input was

[archseer]

Based on the trace in the other issue that seems to be it: #2004 (comment)

[pascalkuthe]

I tried to reproduce this by the various methods described. No matter how long I spam any keys or try I can't reproduce this. Is it possible this has been fixed? There were quite a few reports around April last year but nothing since

[gabydd]

yeah you are correct @pascalkuthe this looks like it was fixed by #3193