From b7c6ffa6c2598dceb4bb4804538e636ed8e85700 Mon Sep 17 00:00:00 2001
From: Conrad Irwin <conrad.irwin@gmail.com>
Date: Fri, 24 Jan 2025 16:14:19 -0700
Subject: [PATCH] Fix panic when multi-cursor edit attempted in deleted hunk
 (#23633)

Release Notes:

- N/A
---
 crates/editor/src/actions.rs            |  2 +-
 crates/editor/src/editor.rs             |  6 ++++
 crates/editor/src/editor_tests.rs       | 39 +++++++++++++++++++++++++
 crates/multi_buffer/src/multi_buffer.rs |  4 +--
 4 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/crates/editor/src/actions.rs b/crates/editor/src/actions.rs
index 658483567f11d366889b2757c9d6ea33465121f7..e1995078a28a0f14f6e5b452d5d7dcea8e88915c 100644
--- a/crates/editor/src/actions.rs
+++ b/crates/editor/src/actions.rs
@@ -372,7 +372,6 @@ gpui::actions!(
         ToggleAutoSignatureHelp,
         ToggleGitBlame,
         ToggleGitBlameInline,
-        ToggleSelectedDiffHunks,
         ToggleIndentGuides,
         ToggleInlayHints,
         ToggleInlineCompletions,
@@ -397,3 +396,4 @@ gpui::actions!(
 action_as!(go_to_line, ToggleGoToLine as Toggle);
 
 action_with_deprecated_aliases!(editor, OpenSelectedFilename, ["editor::OpenFile"]);
+action_with_deprecated_aliases!(editor, ToggleSelectedDiffHunks, ["editor::ToggleDiffHunk"]);
diff --git a/crates/editor/src/editor.rs b/crates/editor/src/editor.rs
index a40d0def338b3eedba2e7d4b1dd2b44476a7873a..3b59ea51f9c5c43c5c246d1ab334e5ee4b8fa321 100644
--- a/crates/editor/src/editor.rs
+++ b/crates/editor/src/editor.rs
@@ -3724,6 +3724,9 @@ impl Editor {
         }
 
         let position = self.selections.newest_anchor().head();
+        if position.diff_base_anchor.is_some() {
+            return;
+        }
         let (buffer, buffer_position) =
             if let Some(output) = self.buffer.read(cx).text_anchor_for_position(position, cx) {
                 output
@@ -4391,6 +4394,9 @@ impl Editor {
     fn refresh_code_actions(&mut self, cx: &mut ViewContext<Self>) -> Option<()> {
         let buffer = self.buffer.read(cx);
         let newest_selection = self.selections.newest_anchor().clone();
+        if newest_selection.head().diff_base_anchor.is_some() {
+            return None;
+        }
         let (start_buffer, start) = buffer.text_anchor_for_position(newest_selection.start, cx)?;
         let (end_buffer, end) = buffer.text_anchor_for_position(newest_selection.end, cx)?;
         if start_buffer != end_buffer {
diff --git a/crates/editor/src/editor_tests.rs b/crates/editor/src/editor_tests.rs
index 6d89af9e8b1456e1f310da92f53921a032016a36..b0d1043438864d3fa8f521c2416fd73d09292e0b 100644
--- a/crates/editor/src/editor_tests.rs
+++ b/crates/editor/src/editor_tests.rs
@@ -13229,6 +13229,45 @@ async fn test_toggling_adjacent_diff_hunks(cx: &mut TestAppContext) {
     "}
         .to_string(),
     );
+
+    cx.set_state(indoc! { "
+        one
+        TWO
+        ˇthree
+        four
+        five
+    "});
+    cx.run_until_parked();
+    cx.update_editor(|editor, cx| {
+        editor.toggle_selected_diff_hunks(&Default::default(), cx);
+    });
+
+    cx.assert_state_with_diff(
+        indoc! { "
+            one
+          - two
+          + TWO
+            ˇthree
+            four
+            five
+        "}
+        .to_string(),
+    );
+    cx.update_editor(|editor, cx| {
+        editor.move_up(&Default::default(), cx);
+        editor.move_up(&Default::default(), cx);
+        editor.toggle_selected_diff_hunks(&Default::default(), cx);
+    });
+    cx.assert_state_with_diff(
+        indoc! { "
+            one
+            ˇTWO
+            three
+            four
+            five
+        "}
+        .to_string(),
+    );
 }
 
 #[gpui::test]
diff --git a/crates/multi_buffer/src/multi_buffer.rs b/crates/multi_buffer/src/multi_buffer.rs
index b489d48227453f58bc9727cdd789b2020896e166..b01c06c474ac4b444de001dcf58d9d24b9cf9b2c 100644
--- a/crates/multi_buffer/src/multi_buffer.rs
+++ b/crates/multi_buffer/src/multi_buffer.rs
@@ -796,7 +796,7 @@ impl MultiBuffer {
         for (ix, (range, new_text)) in edits.into_iter().enumerate() {
             let original_indent_column = original_indent_columns.get(ix).copied().unwrap_or(0);
 
-            cursor.seek_forward(&range.start);
+            cursor.seek(&range.start);
             let mut start_region = cursor.region().expect("start offset out of bounds");
             if !start_region.is_main_buffer {
                 cursor.next();
@@ -2266,7 +2266,7 @@ impl MultiBuffer {
                         diff_hunk.buffer_range.start,
                     );
                 }
-                if diff_hunk.row_range.start.0 == peek_end.row
+                if diff_hunk.row_range.start.0 <= peek_end.row
                     && diff_hunk.excerpt_id == end.excerpt_id
                 {
                     end = Anchor::in_buffer(