Fix bugs in expanding diff hunk (zed-industries#18885)

Release Notes:

- Fixed an issue where diff hunks at the boundaries of multi buffer
excerpts could not be expanded

crates/editor/src/editor_tests.rs

@@ -11715,6 +11715,60 @@ async fn test_toggle_diff_expand_in_multi_buffer(cx: &mut gpui::TestAppContext)
  );
 }
 
+#[gpui::test]
+async fn test_expand_diff_hunk_at_excerpt_boundary(cx: &mut gpui::TestAppContext) {
+ init_test(cx, |_| {});
+
+ let base = "aaa\nbbb\nccc\nddd\neee\nfff\nggg\n";
+ let text = "aaa\nBBB\nBB2\nccc\nDDD\nEEE\nfff\nggg\n";
+
+ let buffer = cx.new_model(|cx| {
+ let mut buffer = Buffer::local(text.to_string(), cx);
+ buffer.set_diff_base(Some(base.into()), cx);
+ buffer
+ });
+
+ let multi_buffer = cx.new_model(|cx| {
+ let mut multibuffer = MultiBuffer::new(ReadWrite);
+ multibuffer.push_excerpts(
+ buffer.clone(),
+ [
+ ExcerptRange {
+ context: Point::new(0, 0)..Point::new(2, 0),
+ primary: None,
+ },
+ ExcerptRange {
+ context: Point::new(5, 0)..Point::new(7, 0),
+ primary: None,
+ },
+ ],
+ cx,
+ );
+ multibuffer
+ });
+
+ let editor = cx.add_window(|cx| Editor::new(EditorMode::Full, multi_buffer, None, true, cx));
+ let mut cx = EditorTestContext::for_editor(editor, cx).await;
+ cx.run_until_parked();
+
+ cx.update_editor(|editor, cx| editor.expand_all_hunk_diffs(&Default::default(), cx));
+ cx.executor().run_until_parked();
+
+ cx.assert_diff_hunks(
+ "
+ aaa
+ - bbb
+ + BBB
+
+ - ddd
+ - eee
+ + EEE
+ fff
+ "
+ .unindent(),
+ );
+}
+
 #[gpui::test]
 async fn test_edits_around_expanded_insertion_hunks(
  executor: BackgroundExecutor,

crates/editor/src/hunk_diff.rs

@@ -209,19 +209,20 @@ impl Editor {
 
  retain
  });
- for remaining_hunk in hunks_to_toggle {
- let remaining_hunk_point_range =
- Point::new(remaining_hunk.row_range.start.0, 0)
- ..Point::new(remaining_hunk.row_range.end.0, 0);
+ for hunk in hunks_to_toggle {
+ let remaining_hunk_point_range = Point::new(hunk.row_range.start.0, 0)
+ ..Point::new(hunk.row_range.end.0, 0);
+ let hunk_start = snapshot
+ .buffer_snapshot
+ .anchor_before(remaining_hunk_point_range.start);
+ let hunk_end = snapshot
+ .buffer_snapshot
+ .anchor_in_excerpt(hunk_start.excerpt_id, hunk.buffer_range.end)
+ .unwrap();
  hunks_to_expand.push(HoveredHunk {
- status: hunk_status(&remaining_hunk),
- multi_buffer_range: snapshot
- .buffer_snapshot
- .anchor_before(remaining_hunk_point_range.start)
- ..snapshot
- .buffer_snapshot
- .anchor_after(remaining_hunk_point_range.end),
- diff_base_byte_range: remaining_hunk.diff_base_byte_range.clone(),
+ status: hunk_status(&hunk),
+ multi_buffer_range: hunk_start..hunk_end,
+ diff_base_byte_range: hunk.diff_base_byte_range.clone(),
  });
  }
 
@@ -246,33 +247,22 @@ impl Editor {
  hunk: &HoveredHunk,
  cx: &mut ViewContext<'_, Editor>,
  ) -> Option<()> {
- let multi_buffer_snapshot = self.buffer().read(cx).snapshot(cx);
+ let buffer = self.buffer.clone();
+ let multi_buffer_snapshot = buffer.read(cx).snapshot(cx);
  let hunk_range = hunk.multi_buffer_range.clone();
- let hunk_point_range = hunk_range.to_point(&multi_buffer_snapshot);
-
- let buffer = self.buffer().clone();
- let snapshot = self.snapshot(cx);
  let (diff_base_buffer, deleted_text_lines) = buffer.update(cx, |buffer, cx| {
- let hunk = buffer_diff_hunk(&snapshot.buffer_snapshot, hunk_point_range.clone())?;
- let mut buffer_ranges = buffer.range_to_buffer_ranges(hunk_point_range, cx);
- if buffer_ranges.len() == 1 {
- let (buffer, _, _) = buffer_ranges.pop()?;
- let diff_base_buffer = diff_base_buffer
- .or_else(|| self.current_diff_base_buffer(&buffer, cx))
- .or_else(|| create_diff_base_buffer(&buffer, cx))?;
- let buffer = buffer.read(cx);
- let deleted_text_lines = buffer.diff_base().map(|diff_base| {
- let diff_start_row = diff_base
- .offset_to_point(hunk.diff_base_byte_range.start)
- .row;
- let diff_end_row = diff_base.offset_to_point(hunk.diff_base_byte_range.end).row;
-
- diff_end_row - diff_start_row
- })?;
- Some((diff_base_buffer, deleted_text_lines))
- } else {
- None
- }
+ let buffer = buffer.buffer(hunk_range.start.buffer_id?)?;
+ let diff_base_buffer = diff_base_buffer
+ .or_else(|| self.current_diff_base_buffer(&buffer, cx))
+ .or_else(|| create_diff_base_buffer(&buffer, cx))?;
+ let deleted_text_lines = buffer.read(cx).diff_base().map(|diff_base| {
+ let diff_start_row = diff_base
+ .offset_to_point(hunk.diff_base_byte_range.start)
+ .row;
+ let diff_end_row = diff_base.offset_to_point(hunk.diff_base_byte_range.end).row;
+ diff_end_row - diff_start_row
+ })?;
+ Some((diff_base_buffer, deleted_text_lines))
  })?;
 
  let block_insert_index = match self.expanded_hunks.hunks.binary_search_by(|probe| {
@@ -1128,21 +1118,6 @@ fn editor_with_deleted_text(
  (editor_height, editor)
 }
 
-fn buffer_diff_hunk(
- buffer_snapshot: &MultiBufferSnapshot,
- row_range: Range<Point>,
-) -> Option<MultiBufferDiffHunk> {
- let mut hunks = buffer_snapshot.git_diff_hunks_in_range(
- MultiBufferRow(row_range.start.row)..MultiBufferRow(row_range.end.row),
- );
- let hunk = hunks.next()?;
- let second_hunk = hunks.next();
- if second_hunk.is_none() {
- return Some(hunk);
- }
- None
-}
-
 impl DisplayDiffHunk {
  pub fn start_display_row(&self) -> DisplayRow {
  match self {
@@ -1209,7 +1184,10 @@ pub fn diff_hunk_to_display(
  let hunk_end_point = Point::new(hunk_end_row.0, 0);
 
  let multi_buffer_start = snapshot.buffer_snapshot.anchor_before(hunk_start_point);
- let multi_buffer_end = snapshot.buffer_snapshot.anchor_after(hunk_end_point);
+ let multi_buffer_end = snapshot
+ .buffer_snapshot
+ .anchor_in_excerpt(multi_buffer_start.excerpt_id, hunk.buffer_range.end)
+ .unwrap();
  let end = hunk_end_point.to_display_point(snapshot).row();
 
  DisplayDiffHunk::Unfolded {

crates/language/src/buffer.rs

@@ -1156,7 +1156,6 @@ impl Buffer {
  this.non_text_state_update_count += 1;
  if let Some(BufferDiffBase::PastBufferVersion { rope, .. }) = &mut this.diff_base {
  *rope = diff_base_rope;
- cx.emit(BufferEvent::DiffBaseChanged);
  }
  cx.emit(BufferEvent::DiffUpdated);
  })