Panic when yank and past from right to left window of the same file

[getreu]

My Helix version is compiled from commit:

commit 38149872989477f62222ce68dc32d2d6018ae165 (HEAD -> master, origin/master, origin/HEAD)
Author: Michael Davis <mcarsondavis@gmail.com>
Date:   Fri Nov 4 11:04:16 2022 -0500

    Fix panic on paste from blackhole register (#4497)

Panic when yank and past from right to left window of the same file

thread 'main' panicked at 'Position 21270 is out of range for changeset len 20356!', helix-core/src/transaction.rs:397:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[David-Else]

I tried the same thing and it worked with no panic, can you provide a step-by-step repeatable way to get this panic?

[emilyyyylime]

Also it'd be useful if you could reproduce the issue with the RUST_BACKTRACE=1 environment variable and share the outputted backtrace

[getreu]

Sorry, I can not reproduce it reliably. But it proves, that this assertion is wrong in some (edge) cases:

        if pos > old_pos {
            panic!(
                "Position {} is out of range for changeset len {}!",
                pos, old_pos
            )
        }

[archseer]

Finally caught a backtrace:

thread 'main' panicked at 'Position 4914 is out of range for changeset len 4842!', helix-core/src/transaction.rs:397:13
stack backtrace:
   0: rust_begin_unwind
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/panicking.rs:143:14
   2: helix_core::transaction::ChangeSet::map_pos
   3: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
   4: helix_core::selection::Selection::map
   5: helix_view::view::View::apply
   6: helix_term::commands::paste_impl
   7: helix_term::commands::paste
   8: helix_term::ui::editor::EditorView::handle_keymap_event::{{closure}}
   9: helix_term::ui::editor::EditorView::handle_keymap_event
  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: hx::main_impl::{{closure}}
  14: std::thread::local::LocalKey<T>::with
  15: tokio::park::thread::CachedParkThread::block_on
  16: tokio::runtime::scheduler::multi_thread::MultiThread::block_on
  17: tokio::runtime::Runtime::block_on
  18: hx::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.