Michael Sloan created
For me this is a panic that started occurring today in my use of Zed.
The repro is to type `ctrl-x` to start a pending key sequence and then
close the collab side panel with the mouse. The issue is that
dispatching the action based on pending keystrokes uses the same
`DispatchNodeId` as when the 1 second timer was started.
`DispatchNodeId` is not stable across frames. This also means that the
wrong `DispatchNodeId` can be used in the non-panicing case, potentially
causing the action to not occur.
The mystery here is why did this only start happening now in my use of
Zed, and why isn't it showing up in the panics dashboard / issue
reports.
Panic looks like
```
{
"thread": "main",
"payload": "index out of bounds: the len is 467 but the index is 1861",
"location_data": {
"file": "crates/gpui/src/key_dispatch.rs",
"line": 519
},
"backtrace": [
"zed::reliability::init_panic_hook::{{closure}}::he1d8257b19b16eec+155265758",
"std::panicking::rust_panic_with_hook::h33b18b24045abff4+128544307",
"std::panicking::begin_panic_handler::{{closure}}::hf8313cc2fd0126bc+128543530",
"std::sys::backtrace::__rust_end_short_backtrace::h57fe07c8aea5c98a+128537145",
"__rustc[95feac21a9532783]::rust_begin_unwind+128542669",
"core::panicking::panic_fmt::hd54fb667be51beea+9456688",
"core::panicking::panic_bounds_check::h1a9bf3d94de0fc80+9457170",
"gpui::key_dispatch::DispatchTree::dispatch_path::hce77d277881569bf+73992023",
"gpui::app::App::spawn::{{closure}}::hb1e79bbbdead3012+73687056",
"async_task::raw::RawTask<F,T,S,M>::run::hd13f66f99bb24bbd+70694231",
"<gpui::platform::linux::x11::client::X11Client as gpui::platform::linux::platform::LinuxClient>::run::h5a92ddaaf9a06dd1+74465138",
"gpui::platform::linux::platform::<impl gpui::platform::Platform for P>::run::hd19ac52b2d94268e+74064525",
"gpui::app::Application::run::hee83110c717a5af0+151862692",
"zed::main::hca7e2265584c4139+153307630",
"std::sys::backtrace::__rust_begin_short_backtrace::h2e04f4034c2d82c5+153146899",
"std::rt::lang_start::{{closure}}::h91cf1ca0eeae23ae+154454121",
"std::rt::lang_start_internal::h418648f91f5be3a1+128467809",
"main+153326748",
"__libc_start_call_main+25056432783818",
"__libc_start_main_impl+25056432784011",
"_start+12389486"
],
"app_version": "0.190.6",
"app_commit_sha": "9a2dcbbe244407fed51d61f38e4a4a59ec1cccc6",
"release_channel": "stable",
"target": "x86_64-unknown-linux-gnu",
"os_name": "Linux X11",
"os_version": "ubuntu 24.04",
"architecture": "x86_64",
"panicked_on": 1750185799233,
"system_id": "abae7201-61fb-442b-922b-202071ae81c0",
"installation_id": "69a0fb9a-11a2-4065-ad8c-b281e68525ad",
"session_id": "bc5b5f2f-e4c3-44a8-948e-c0550a2e2ef2"
}
```
Release Notes:
- Fixed a rare panic / potential incorrect action dispatch when a
pending keysequence is applied after the 1 second timer elapsing.crates/gpui/src/key_dispatch.rs | 2
crates/gpui/src/window.rs | 71 +++++++++-------------------------
2 files changed, 22 insertions(+), 51 deletions(-)
@@ -63,6 +63,8 @@ use std::{
rc::Rc,
};
+/// ID of a node within `DispatchTree`. Note that these are **not** stable between frames, and so a
+/// `DispatchNodeId` should only be used with the `DispatchTree` that provided it.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub(crate) struct DispatchNodeId(usize);
@@ -1318,21 +1318,13 @@ impl Window {
/// Dispatch the given action on the currently focused element.
pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
- let focus_handle = self.focused(cx);
+ let focus_id = self.focused(cx).map(|handle| handle.id);
let window = self.handle;
cx.defer(move |cx| {
window
.update(cx, |_, window, cx| {
- let node_id = focus_handle
- .and_then(|handle| {
- window
- .rendered_frame
- .dispatch_tree
- .focusable_node_id(handle.id)
- })
- .unwrap_or_else(|| window.rendered_frame.dispatch_tree.root_node_id());
-
+ let node_id = window.focus_node_id_in_rendered_frame(focus_id);
window.dispatch_action_on_node(node_id, action.as_ref(), cx);
})
.log_err();
@@ -1709,17 +1701,11 @@ impl Window {
/// Determine whether the given action is available along the dispatch path to the currently focused element.
pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
- let target = self
- .focused(cx)
- .and_then(|focused_handle| {
- self.rendered_frame
- .dispatch_tree
- .focusable_node_id(focused_handle.id)
- })
- .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
+ let node_id =
+ self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
self.rendered_frame
.dispatch_tree
- .is_action_available(action, target)
+ .is_action_available(action, node_id)
}
/// The position of the mouse relative to the window.
@@ -3484,15 +3470,7 @@ impl Window {
self.draw(cx);
}
- let node_id = self
- .focus
- .and_then(|focus_id| {
- self.rendered_frame
- .dispatch_tree
- .focusable_node_id(focus_id)
- })
- .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
-
+ let node_id = self.focus_node_id_in_rendered_frame(self.focus);
let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
let mut keystroke: Option<Keystroke> = None;
@@ -3564,6 +3542,7 @@ impl Window {
return;
};
+ let node_id = window.focus_node_id_in_rendered_frame(window.focus);
let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
let to_replay = window
@@ -3695,15 +3674,7 @@ impl Window {
}
fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
- let node_id = self
- .focus
- .and_then(|focus_id| {
- self.rendered_frame
- .dispatch_tree
- .focusable_node_id(focus_id)
- })
- .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
-
+ let node_id = self.focus_node_id_in_rendered_frame(self.focus);
let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
'replay: for replay in replays {
@@ -3739,6 +3710,16 @@ impl Window {
}
}
+ fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
+ focus_id
+ .and_then(|focus_id| {
+ self.rendered_frame
+ .dispatch_tree
+ .focusable_node_id(focus_id)
+ })
+ .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
+ }
+
fn dispatch_action_on_node(
&mut self,
node_id: DispatchNodeId,
@@ -3946,12 +3927,8 @@ impl Window {
/// Returns the current context stack.
pub fn context_stack(&self) -> Vec<KeyContext> {
+ let node_id = self.focus_node_id_in_rendered_frame(self.focus);
let dispatch_tree = &self.rendered_frame.dispatch_tree;
- let node_id = self
- .focus
- .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
- .unwrap_or_else(|| dispatch_tree.root_node_id());
-
dispatch_tree
.dispatch_path(node_id)
.iter()
@@ -3961,15 +3938,7 @@ impl Window {
/// Returns all available actions for the focused element.
pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
- let node_id = self
- .focus
- .and_then(|focus_id| {
- self.rendered_frame
- .dispatch_tree
- .focusable_node_id(focus_id)
- })
- .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
-
+ let node_id = self.focus_node_id_in_rendered_frame(self.focus);
let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
for action_type in cx.global_action_listeners.keys() {
if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {