Fix issues around up arrow event edit shortcut (#9645)

test/utils/EventUtils-test.ts

@@ -34,6 +34,7 @@ import {
     canEditContent,
     canEditOwnEvent,
     fetchInitialEvent,
+    findEditableEvent,
     isContentActionable,
     isLocationEvent,
     isVoiceMessage,
@@ -430,4 +431,13 @@ describe('EventUtils', () => {
             expect(room.getThread(THREAD_ROOT)).toBeInstanceOf(Thread);
         });
     });
+
+    describe("findEditableEvent", () => {
+        it("should not explode when given empty events array", () => {
+            expect(findEditableEvent({
+                events: [],
+                isForward: true,
+            })).toBeUndefined();
+        });
+    });
 });