Not Implemented Panic on [ "extend_line", "delete_selection", "open_above" ] depending on keybind

[diktomat]

Summary

In my ongoing quest to battle Helix's behavior with newlines, I added x = { c = [ "extend_line", "delete_selection", "open_above" ] } to my config.toml. While working as intended, I had to realize this breaks every other use of x, so I changed the binding to use S instead. Having changed nothing but the key, it panics with not implemented.

Reproduction Steps

I tried this:

1. Set the keybind in config.toml: S = [ "extend_line", "delete_selection", "open_above" ]
2. Use it.

I expected this to happen:
It works, as it does when set to xc.

Instead, this happened:

❯ RUST_BACKTRACE=1 hx src/lib.rs 
thread 'main' panicked at 'not implemented', helix-term/src/ui/editor.rs:1230:34
stack backtrace:
   0: _rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: <helix_term::ui::editor::EditorView as helix_term::compositor::Component>::handle_event
   4: helix_term::compositor::Compositor::handle_event
   5: helix_term::application::Application::handle_terminal_events
   6: helix_term::application::Application::event_loop_until_idle::{{closure}}
   7: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   8: std::thread::local::LocalKey<T>::with
   9: tokio::park::thread::CachedParkThread::block_on
  10: tokio::runtime::thread_pool::ThreadPool::block_on
  11: tokio::runtime::Runtime::block_on
  12: hx::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Helix log

No response

Platform

macOS 12.5.1

Terminal Emulator

Kitty 0.25.2

Helix Version

22.05-418-g18909aa

[the-mikedavis]

Duplicate of #2051

[diktomat]

I actually don't believe this to be a duplicate (I've seen #2051 before submitting the issue), as it works when set to xc, but please just keep it closed if I'm wrong:

S = [ "extend_line", "delete_selection", "open_above" ]           # panic
x = { c = [ "extend_line", "delete_selection", "open_above" ] }   # fine

[the-mikedavis]

The panic for S comes from the unimplemented! in #2051:

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

Lines 1225 to 1229 in ccae718

	self.last_insert.0 = match self.keymaps.get(mode, key) {
	KeymapResult::Matched(command) => command,
	// FIXME: insert mode can only be entered through single KeyCodes
	_ => unimplemented!(),
	};

That block assumes that you are only entering insert mode by a single key bound to a single command. xc should panic from that same unimplemented! but currently the lookup of xc in self.keymaps.get(mode, key) mistakenly only looks up the c key event which gives KeymapResult::Matched(MappableCommand("change_selection")) - the binding for c. It looks like both problems are solved by #2634