Restore scroll after undo edit prediction (#31162)

Closes #29652

Release Notes:

- Fixed an issue where the scroll and cursor position would not be
restored after undoing an inline completion

crates/editor/src/editor.rs

@@ -6523,6 +6523,10 @@ impl Editor {
                     provider.accept(cx);
                 }
 
+                // Store the transaction ID and selections before applying the edit
+                let transaction_id_prev =
+                    self.buffer.read_with(cx, |b, cx| b.last_transaction_id(cx));
+
                 let snapshot = self.buffer.read(cx).snapshot(cx);
                 let last_edit_end = edits.last().unwrap().0.end.bias_right(&snapshot);
 
@@ -6531,9 +6535,20 @@ impl Editor {
                 });
 
                 self.change_selections(None, window, cx, |s| {
-                    s.select_anchor_ranges([last_edit_end..last_edit_end])
+                    s.select_anchor_ranges([last_edit_end..last_edit_end]);
                 });
 
+                let selections = self.selections.disjoint_anchors();
+                if let Some(transaction_id_now) =
+                    self.buffer.read_with(cx, |b, cx| b.last_transaction_id(cx))
+                {
+                    let has_new_transaction = transaction_id_prev != Some(transaction_id_now);
+                    if has_new_transaction {
+                        self.selection_history
+                            .insert_transaction(transaction_id_now, selections);
+                    }
+                }
+
                 self.update_visible_inline_completion(window, cx);
                 if self.active_inline_completion.is_none() {
                     self.refresh_inline_completion(true, true, window, cx);

crates/editor/src/editor_tests.rs

@@ -1,6 +1,7 @@
 use super::*;
 use crate::{
     JoinLines,
+    inline_completion_tests::FakeInlineCompletionProvider,
     linked_editing_ranges::LinkedEditingRanges,
     scroll::scroll_amount::ScrollAmount,
     test::{
@@ -6380,6 +6381,98 @@ async fn test_undo_format_scrolls_to_last_edit_pos(cx: &mut TestAppContext) {
     "});
 }
 
+#[gpui::test]
+async fn test_undo_inline_completion_scrolls_to_edit_pos(cx: &mut TestAppContext) {
+    init_test(cx, |_| {});
+
+    let mut cx = EditorTestContext::new(cx).await;
+
+    let provider = cx.new(|_| FakeInlineCompletionProvider::default());
+    cx.update_editor(|editor, window, cx| {
+        editor.set_edit_prediction_provider(Some(provider.clone()), window, cx);
+    });
+
+    cx.set_state(indoc! {"
+        line 1
+        line 2
+        linˇe 3
+        line 4
+        line 5
+        line 6
+        line 7
+        line 8
+        line 9
+        line 10
+    "});
+
+    let snapshot = cx.buffer_snapshot();
+    let edit_position = snapshot.anchor_after(Point::new(2, 4));
+
+    cx.update(|_, cx| {
+        provider.update(cx, |provider, _| {
+            provider.set_inline_completion(Some(inline_completion::InlineCompletion {
+                id: None,
+                edits: vec![(edit_position..edit_position, "X".into())],
+                edit_preview: None,
+            }))
+        })
+    });
+
+    cx.update_editor(|editor, window, cx| editor.update_visible_inline_completion(window, cx));
+    cx.update_editor(|editor, window, cx| {
+        editor.accept_edit_prediction(&crate::AcceptEditPrediction, window, cx)
+    });
+
+    cx.assert_editor_state(indoc! {"
+        line 1
+        line 2
+        lineXˇ 3
+        line 4
+        line 5
+        line 6
+        line 7
+        line 8
+        line 9
+        line 10
+    "});
+
+    cx.update_editor(|editor, window, cx| {
+        editor.change_selections(None, window, cx, |s| {
+            s.select_ranges([Point::new(9, 2)..Point::new(9, 2)]);
+        });
+    });
+
+    cx.assert_editor_state(indoc! {"
+        line 1
+        line 2
+        lineX 3
+        line 4
+        line 5
+        line 6
+        line 7
+        line 8
+        line 9
+        liˇne 10
+    "});
+
+    cx.update_editor(|editor, window, cx| {
+        editor.undo(&Default::default(), window, cx);
+    });
+
+    cx.assert_editor_state(indoc! {"
+        line 1
+        line 2
+        lineˇ 3
+        line 4
+        line 5
+        line 6
+        line 7
+        line 8
+        line 9
+        line 10
+    "});
+}
+
 #[gpui::test]
 async fn test_select_next_with_multiple_carets(cx: &mut TestAppContext) {
     init_test(cx, |_| {});

crates/editor/src/inline_completion_tests.rs

@@ -302,8 +302,8 @@ fn assign_editor_completion_provider(
 }
 
 #[derive(Default, Clone)]
-struct FakeInlineCompletionProvider {
-    completion: Option<inline_completion::InlineCompletion>,
+pub struct FakeInlineCompletionProvider {
+    pub completion: Option<inline_completion::InlineCompletion>,
 }
 
 impl FakeInlineCompletionProvider {