From 1c4c568068b067f08b03e6cdf53e80d86fa35966 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Fri, 28 Feb 2025 16:02:35 -0800
Subject: [PATCH] Allow unfolding deleted buffers in project diff w/ keyboard
 (#25835)

Release Notes:

- N/A
---
 crates/editor/src/editor.rs                   | 19 ++++++++++---------
 crates/multi_buffer/src/multi_buffer.rs       |  4 +++-
 crates/multi_buffer/src/multi_buffer_tests.rs | 19 +++++++++++++++++++
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/crates/editor/src/editor.rs b/crates/editor/src/editor.rs
index 47eb8495e9b157bf5f54a1c9c323de2a6045560f..dc0f5fc88b549e74dea7b6aa7fb30cfdaf0b3591 100644
--- a/crates/editor/src/editor.rs
+++ b/crates/editor/src/editor.rs
@@ -13018,11 +13018,11 @@ impl Editor {
             self.fold_creases(to_fold, true, window, cx);
         } else {
             let multi_buffer_snapshot = self.buffer.read(cx).snapshot(cx);
-
-            let buffer_ids: HashSet<_> = multi_buffer_snapshot
-                .ranges_to_buffer_ranges(self.selections.disjoint_anchor_ranges())
-                .map(|(snapshot, _, _)| snapshot.remote_id())
-                .collect();
+            let buffer_ids = self
+                .selections
+                .disjoint_anchor_ranges()
+                .flat_map(|range| multi_buffer_snapshot.buffer_ids_for_range(range))
+                .collect::<HashSet<_>>();
             for buffer_id in buffer_ids {
                 self.fold_buffer(buffer_id, cx);
             }
@@ -13195,10 +13195,11 @@ impl Editor {
             self.unfold_ranges(&ranges, true, true, cx);
         } else {
             let multi_buffer_snapshot = self.buffer.read(cx).snapshot(cx);
-            let buffer_ids: HashSet<_> = multi_buffer_snapshot
-                .ranges_to_buffer_ranges(self.selections.disjoint_anchor_ranges())
-                .map(|(snapshot, _, _)| snapshot.remote_id())
-                .collect();
+            let buffer_ids = self
+                .selections
+                .disjoint_anchor_ranges()
+                .flat_map(|range| multi_buffer_snapshot.buffer_ids_for_range(range))
+                .collect::<HashSet<_>>();
             for buffer_id in buffer_ids {
                 self.unfold_buffer(buffer_id, cx);
             }
diff --git a/crates/multi_buffer/src/multi_buffer.rs b/crates/multi_buffer/src/multi_buffer.rs
index 21d657775f8fe8a72b33e7a06ada672ba2d7566a..e943e797ab2e4c3b2db2e6e2e7d99d8e3c644570 100644
--- a/crates/multi_buffer/src/multi_buffer.rs
+++ b/crates/multi_buffer/src/multi_buffer.rs
@@ -3541,7 +3541,9 @@ impl MultiBufferSnapshot {
         cursor.seek(&range.start);
         std::iter::from_fn(move || {
             let region = cursor.region()?;
-            if region.range.start >= range.end {
+            if region.range.start > range.end
+                || region.range.start == range.end && region.range.start > range.start
+            {
                 return None;
             }
             cursor.next_excerpt();
diff --git a/crates/multi_buffer/src/multi_buffer_tests.rs b/crates/multi_buffer/src/multi_buffer_tests.rs
index e878e50dd22478d0cb1507024508af5ea7baf863..bac946ba84b57bcf0afeb113c6879ebf5253c044 100644
--- a/crates/multi_buffer/src/multi_buffer_tests.rs
+++ b/crates/multi_buffer/src/multi_buffer_tests.rs
@@ -2035,6 +2035,25 @@ fn test_diff_hunks_with_multiple_excerpts(cx: &mut TestAppContext) {
         ]
     );
 
+    let buffer_ids_by_range = [
+        (Point::new(0, 0)..Point::new(0, 0), &[id_1] as &[_]),
+        (Point::new(0, 0)..Point::new(2, 0), &[id_1]),
+        (Point::new(2, 0)..Point::new(2, 0), &[id_1]),
+        (Point::new(3, 0)..Point::new(3, 0), &[id_1]),
+        (Point::new(8, 0)..Point::new(9, 0), &[id_1]),
+        (Point::new(8, 0)..Point::new(10, 0), &[id_1, id_2]),
+        (Point::new(9, 0)..Point::new(9, 0), &[id_2]),
+    ];
+    for (range, buffer_ids) in buffer_ids_by_range {
+        assert_eq!(
+            snapshot
+                .buffer_ids_for_range(range.clone())
+                .collect::<Vec<_>>(),
+            buffer_ids,
+            "buffer_ids_for_range({range:?}"
+        );
+    }
+
     assert_position_translation(&snapshot);
     assert_line_indents(&snapshot);