Helix crashes when using search mode across windows

[AccessViolation95]

Summary

When using vnew to vertically split the screen, creating a new window, then searching for something in that window with / which causes matching text to be selected, not pressing enter, and then switching focus to the other window and pressing backspace, Helix panics.

Reproduction Steps

I tried this:

1. hx
2. :vnew
3. :tutor (I've verified it works with any text, but just using tutor is easier to follow for this report)
4. /align (Search for text that appears in the window, it can be anything so long as it causes text to be selected. Note that I'm not pressing enter).
5. [left mouse button click on the empty original window on the left]
6. backspace

I expected this to happen:
A character is removed from the searched-for text.

Instead, this happened:
Helix panics with this:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Byte index out of bounds: byte index 19267, Rope/RopeSlice byte length 1', /build/helix-4G9og3/helix-23.05/vendor/ropey/src/slice.rs:324:41
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Helix log

~/.cache/helix/helix.log

2023-08-30T16:13:11.844 helix_view::clipboard [DEBUG] Using xclip to interact with the system and selection (primary) clipboard
2023-08-30T16:13:11.845 helix_tui::backend::crossterm [DEBUG] The keyboard enhancement protocol is not supported in this terminal (checked in 149.191µs)
2023-08-30T16:13:11.845 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:12.246 helix_term::application [DEBUG] received editor event: IdleTimer
2023-08-30T16:13:13.881 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:14.282 helix_term::application [DEBUG] received editor event: IdleTimer
2023-08-30T16:13:14.512 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:14.670 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:14.773 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:14.912 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:15.917 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:15.917 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:16.327 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:16.327 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:16.596 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:16.596 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:16.728 helix_term::application [DEBUG] received editor event: IdleTimer
2023-08-30T16:13:16.774 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:16.774 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:16.885 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:16.885 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:17.057 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:17.057 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:17.155 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:17.155 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:17.684 helix_vcs [INFO] Error {
    context: "failed to open git repo",
    source: Discover(
        NoGitRepository {
            path: "/var/lib/helix/runtime",
        },
    ),
}
2023-08-30T16:13:17.684 helix_vcs [INFO] failed to open diff base for /var/lib/helix/runtime/tutor
2023-08-30T16:13:17.684 helix_vcs [INFO] Error {
    context: "failed to open git repo",
    source: Discover(
        NoGitRepository {
            path: "/var/lib/helix/runtime",
        },
    ),
}
2023-08-30T16:13:17.684 helix_vcs [INFO] failed to obtain current head name for /var/lib/helix/runtime/tutor
2023-08-30T16:13:17.684 helix_view::document [DEBUG] id 2 modified - last saved: 0, current: 0
2023-08-30T16:13:17.685 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:17.685 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:18.758 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:18.758 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:18.969 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:18.969 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:19.159 helix_term::application [DEBUG] received editor event: IdleTimer
2023-08-30T16:13:19.229 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:19.229 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:19.306 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:19.306 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:19.529 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:19.529 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:19.605 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:19.605 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:20.724 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2023-08-30T16:13:20.724 helix_view::document [DEBUG] id 3 modified - last saved: 0, current: 0
2023-08-30T16:13:21.305 helix_term::application [DEBUG] received editor event: IdleTimer

Platform

Linux

Terminal Emulator

alacritty 0.12.2

Helix Version

helix 23.05 (7f5940b)

[pascalkuthe]

Yeah clicking on a different view is the problem. This bug that is currently blocked on #5581.

Duplicate of #5632