Apply inversions to Views on undo/redo

When using undo/redo, the history revision can be decremented. In that
case we should apply the inversions since the given revision in
History::changes_since. This prevents panics with jumplist operations
when a session uses undo/redo to move the jumplist selection outside
of the document.
This commit is contained in:
Michael Davis 2022-11-23 09:35:07 -06:00 committed by Blaž Hrastnik
parent fd00f3a70e
commit 4a103db622
3 changed files with 24 additions and 11 deletions

View File

@ -122,17 +122,21 @@ pub const fn at_root(&self) -> bool {
/// Returns the changes since the given revision composed into a transaction.
/// Returns None if there are no changes between the current and given revisions.
pub fn changes_since(&self, revision: usize) -> Option<Transaction> {
if self.at_root() || self.current >= revision {
return None;
}
use std::cmp::Ordering::*;
// The bounds are checked in the if condition above:
// `revision` is known to be `< self.current`.
self.revisions[revision..self.current]
match revision.cmp(&self.current) {
Equal => None,
Greater => self.revisions[self.current + 1..=revision]
.iter()
.map(|revision| &revision.inversion)
.cloned()
.reduce(|acc, inversion| acc.compose(inversion)),
Less => self.revisions[revision + 1..=self.current]
.iter()
.map(|revision| &revision.transaction)
.cloned()
.reduce(|acc, transaction| acc.compose(transaction))
.reduce(|acc, transaction| acc.compose(transaction)),
}
}
/// Undo the last edit.

View File

@ -1424,7 +1424,7 @@ fn handle_event(
// If the current document has been changed, apply the changes to all views.
// This ensures that selections in jumplists follow changes.
if doc.id() == original_doc_id
&& doc.get_current_revision() > original_doc_revision
&& doc.get_current_revision() != original_doc_revision
{
if let Some(transaction) =
doc.history.get_mut().changes_since(original_doc_revision)

View File

@ -286,6 +286,15 @@ async fn test_multi_selection_shell_commands() -> anyhow::Result<()> {
#[tokio::test(flavor = "multi_thread")]
async fn test_undo_redo() -> anyhow::Result<()> {
// A jumplist selection is created at a point which is undone.
//
// * 2[<space> Add two newlines at line start. We're now on line 3.
// * <C-s> Save the selection on line 3 in the jumplist.
// * u Undo the two newlines. We're now on line 1.
// * <C-o><C-i> Jump forward an back again in the jumplist. This would panic
// if the jumplist were not being updated correctly.
test(("#[|]#", "2[<space><C-s>u<C-o><C-i>", "#[|]#")).await?;
// A jumplist selection is passed through an edit and then an undo and then a redo.
//
// * [<space> Add a newline at line start. We're now on line 2.