fix panic displaying delete/delete conflicts, which have no diff

CHANGELOG.md

@@ -7,6 +7,7 @@ This version is based on Jujutsu 0.20.
 - `gg.queries.log-page-size` setting was not being respected.
 - Removed <CR> character which rendered as a circle in the author display on some Linux systems.
 - Improved button/control font display on Linux.
+- Fixed a panic attempting to display delete/delete conflicts in the right pane.
 
 ## [0.18.0](releases/tag/v0.18.0) 
 This version is based on Jujutsu 0.18.

src-tauri/src/worker/queries.rs

@@ -297,10 +297,12 @@ pub fn query_revision(ws: &WorkspaceSession, id: RevId) -> Result<RevResult> {
                     MaterializedTreeValue::Conflict { contents, .. } => {
                         let mut hunks = get_unified_hunks(3, &contents, &[])?;
 
-                        conflicts.push(RevConflict {
-                            path: ws.format_path(path),
-                            hunk: hunks.pop().unwrap(),
-                        });
+                        if let Some(hunk) = hunks.pop() {
+                            conflicts.push(RevConflict {
+                                path: ws.format_path(path),
+                                hunk,
+                            });
+                        }
                     }
                     _ => {
                         log::warn!("nonresolved tree entry did not materialise as conflict");