From 48ceefc2d0aea678e8679d0cef2102aac562f6e4 Mon Sep 17 00:00:00 2001
From: Benjamin Armintor <armintor@gmail.com>
Date: Tue, 27 Aug 2024 12:42:27 -0400
Subject: [PATCH] COLUMBIA: guard against undefined window property in
 companionWindows selector - see also
 https://github.com/ProjectMirador/mirador/issues/3930

---
 src/state/selectors/companionWindows.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/state/selectors/companionWindows.js b/src/state/selectors/companionWindows.js
index ea91987ef..5d47ed86b 100644
--- a/src/state/selectors/companionWindows.js
+++ b/src/state/selectors/companionWindows.js
@@ -74,7 +74,7 @@ const getCompanionWindowsByWindowAndPosition = createSelector(
     (Object.keys(windows) || []).reduce((obj, id) => ({
       ...obj,
       [id]: groupBy(
-        windows[id].companionWindowIds.map(cwid => companionWindows[cwid]),
+        (windows[id].companionWindowIds || []).map(cwid => companionWindows[cwid]),
         cw => cw.position,
       ),
     }), {})