From 54b1c9efca00df99bc3a502fe76d3bbf98938b96 Mon Sep 17 00:00:00 2001
From: Jim Procter <jprocter@dundee.ac.uk>
Date: Fri, 4 Oct 2024 16:03:38 +0100
Subject: [PATCH] JAL-4470 fix: check for workers!=null before checking its
 empty...

---
 src/jalview/gui/PopupMenu.java |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/jalview/gui/PopupMenu.java b/src/jalview/gui/PopupMenu.java
index f4dd579..31e7cbb 100644
--- a/src/jalview/gui/PopupMenu.java
+++ b/src/jalview/gui/PopupMenu.java
@@ -1779,7 +1779,7 @@ public class PopupMenu extends JPopupMenu implements ColourChangeListener
     List<AlignCalcWorkerI> workers = ap.alignFrame.getViewport()
             .getCalcManager().getRegisteredWorkersOfClass(
                     SecondaryStructureConsensusThread.class);
-    if (!workers.isEmpty())
+    if (workers!=null && !workers.isEmpty())
     {
 
       ap.alignFrame.getViewport().getCalcManager()
-- 
1.7.10.2