From 873bf9da6abdeb24cd8624330b7b9977feb79bef Mon Sep 17 00:00:00 2001
From: amwaterhouse <Andrew Waterhouse>
Date: Tue, 14 Dec 2004 11:18:12 +0000
Subject: [PATCH] If groups doesnt contain group, addition is allowed

---
 src/jalview/datamodel/Alignment.java |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/jalview/datamodel/Alignment.java b/src/jalview/datamodel/Alignment.java
index abc7cf6..e329cc8 100755
--- a/src/jalview/datamodel/Alignment.java
+++ b/src/jalview/datamodel/Alignment.java
@@ -342,7 +342,8 @@ public class Alignment implements AlignmentI
 
   /**    */
   public void addGroup(SequenceGroup sg) {
-    groups.addElement(sg);
+    if(!groups.contains(sg))
+      groups.addElement(sg);
   }
 
   /**    */
-- 
1.7.10.2