go_to_line: avoid byte slicing crash in short status labels

Signed-off-by: Xiaobo Liu <[email protected]>

Author: cppcoffee

crates/go_to_line/src/cursor_position.rs

@@ -1,7 +1,7 @@
 use editor::{Editor, MultiBufferSnapshot};
 use gpui::{App, Entity, FocusHandle, Focusable, Styled, Subscription, Task, WeakEntity};
 use settings::Settings;
-use std::{fmt::Write, num::NonZeroU32, time::Duration};
+use std::{borrow::Cow, fmt::Write, num::NonZeroU32, time::Duration};
 use text::{Point, Selection};
 use ui::{
     Button, ButtonCommon, Clickable, Context, FluentBuilder, IntoElement, LabelSize, ParentElement,
@@ -182,13 +182,20 @@ impl CursorPosition {
             if wrote_once {
                 write!(text, ", ").unwrap();
             }
-            let name = if is_short_format { &name[..1] } else { name };
+            let display_name: Cow<'_, str> = if is_short_format {
+                name.chars()
+                    .next()
+                    .map(|c| Cow::Owned(c.to_string()))
+                    .unwrap_or_else(|| Cow::Borrowed(name))
+            } else {
+                Cow::Borrowed(name)
+            };
             let plural_suffix = if count > 1 && !is_short_format {
                 "s"
             } else {
                 ""
             };
-            write!(text, "{count} {name}{plural_suffix}").unwrap();
+            write!(text, "{count} {display_name}{plural_suffix}").unwrap();
             wrote_once = true;
         }
         text.push(')');