Do not panic if entered unknown code via stack trace

e.g. Rust std library

helix-term/src/application.rs

@@ -324,17 +324,21 @@ impl Application {
                             .unwrap();
 
                         let (view, doc) = current!(self.editor);
-                        log::info!("{:?}", doc);
-                        let start = doc.text().line_to_char(line - 1) + column;
+
+                        let text_end = doc.text().len_chars() - 1;
+                        let start = doc.text().try_line_to_char(line - 1).unwrap_or(0) + column;
                         if let Some(end_line) = end_line {
-                            let end =
-                                doc.text().line_to_char(end_line - 1) + end_column.unwrap_or(0);
+                            let end = doc.text().try_line_to_char(end_line - 1).unwrap_or(0)
+                                + end_column.unwrap_or(0);
                             doc.set_selection(
                                 view.id,
-                                Selection::new(smallvec![Range::new(start, end)], 0),
+                                Selection::new(
+                                    smallvec![Range::new(start.min(text_end), end.min(text_end))],
+                                    0,
+                                ),
                             );
                         } else {
-                            doc.set_selection(view.id, Selection::point(start));
+                            doc.set_selection(view.id, Selection::point(start.min(text_end)));
                         }
                         align_view(doc, view, Align::Center);
                     }