From 0df1e4a489f993e092c3e8134966066dc5b6944d Mon Sep 17 00:00:00 2001
From: Cole Miller <cole@zed.dev>
Date: Tue, 11 Mar 2025 03:04:56 -0400
Subject: [PATCH] Address out-of-bounds panic in inline completion button
 (#26394)

Closes #26350

Release Notes:

- Git Beta: Fixed a panic that could occur when using the project diff
---
 crates/multi_buffer/src/multi_buffer.rs       | 10 ++++++++--
 crates/multi_buffer/src/multi_buffer_tests.rs | 11 +++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/crates/multi_buffer/src/multi_buffer.rs b/crates/multi_buffer/src/multi_buffer.rs
index d9a00dcbed..1b1d691b53 100644
--- a/crates/multi_buffer/src/multi_buffer.rs
+++ b/crates/multi_buffer/src/multi_buffer.rs
@@ -4175,6 +4175,9 @@ impl MultiBufferSnapshot {
         let region = cursor.region()?;
         let overshoot = offset - region.range.start;
         let buffer_offset = region.buffer_range.start + overshoot;
+        if buffer_offset > region.buffer.len() {
+            return None;
+        }
         Some((region.buffer, buffer_offset))
     }
 
@@ -4183,8 +4186,11 @@ impl MultiBufferSnapshot {
         cursor.seek(&point);
         let region = cursor.region()?;
         let overshoot = point - region.range.start;
-        let buffer_offset = region.buffer_range.start + overshoot;
-        Some((region.buffer, buffer_offset, region.is_main_buffer))
+        let buffer_point = region.buffer_range.start + overshoot;
+        if buffer_point > region.buffer.max_point() {
+            return None;
+        }
+        Some((region.buffer, buffer_point, region.is_main_buffer))
     }
 
     pub fn suggested_indents(
diff --git a/crates/multi_buffer/src/multi_buffer_tests.rs b/crates/multi_buffer/src/multi_buffer_tests.rs
index 2a3d1727cd..8b10b787da 100644
--- a/crates/multi_buffer/src/multi_buffer_tests.rs
+++ b/crates/multi_buffer/src/multi_buffer_tests.rs
@@ -3378,6 +3378,17 @@ fn assert_position_translation(snapshot: &MultiBufferSnapshot) {
             }
         }
     }
+
+    let point = snapshot.max_point();
+    let Some((buffer, offset)) = snapshot.point_to_buffer_offset(point) else {
+        return;
+    };
+    assert!(offset <= buffer.len(),);
+
+    let Some((buffer, point, _)) = snapshot.point_to_buffer_point(point) else {
+        return;
+    };
+    assert!(point <= buffer.max_point(),);
 }
 
 fn assert_line_indents(snapshot: &MultiBufferSnapshot) {