From a642addccf3a4ee25b3caa8cc7c6ee1f9b0a9ecb Mon Sep 17 00:00:00 2001
From: Conrad Irwin <conrad.irwin@gmail.com>
Date: Fri, 25 Apr 2025 11:12:16 -0600
Subject: [PATCH] Maybe fix panic (#29352)

Since around the time we shipped block diagnostics, we've been seeing an
out of range panic in the editor.

Although the code is heavily inlined, so the stacktrace is missing, this
seems like a likely place that indexing may have gone wrong.

Release Notes:

- Fixed a rare panic in the editor
---
 crates/editor/src/element.rs | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/crates/editor/src/element.rs b/crates/editor/src/element.rs
index d919e24a84..0ecbdab07c 100644
--- a/crates/editor/src/element.rs
+++ b/crates/editor/src/element.rs
@@ -2771,19 +2771,21 @@ impl EditorElement {
                         text_x + layout.width,
                     ))
                 };
-                x_position = if rows.contains(&align_to.row()) {
-                    x_and_width(&line_layouts[align_to.row().minus(rows.start) as usize])
-                } else {
-                    x_and_width(&layout_line(
-                        align_to.row(),
-                        snapshot,
-                        &self.style,
-                        editor_width,
-                        is_row_soft_wrapped,
-                        window,
-                        cx,
-                    ))
-                };
+                let line_ix = align_to.row().0.checked_sub(rows.start.0);
+                x_position =
+                    if let Some(layout) = line_ix.and_then(|ix| line_layouts.get(ix as usize)) {
+                        x_and_width(&layout)
+                    } else {
+                        x_and_width(&layout_line(
+                            align_to.row(),
+                            snapshot,
+                            &self.style,
+                            editor_width,
+                            is_row_soft_wrapped,
+                            window,
+                            cx,
+                        ))
+                    };
 
                 let anchor_x = x_position.unwrap().0;