X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fdatamodel%2FAlignment.java;h=2dafc0c96ec121c9ac7521ef6160aa5084ce0c4d;hb=aa2c6fc3fbfa5a5a60ffd3bfeb6321f1d5e4a2f2;hp=db6195a6d6d1352479f4abf44660bc591b0402a0;hpb=f3f90b8d541ef383d4f1d4cb3c1947200d6983ed;p=jalview.git

diff --git a/src/jalview/datamodel/Alignment.java b/src/jalview/datamodel/Alignment.java
index db6195a..2dafc0c 100755
--- a/src/jalview/datamodel/Alignment.java
+++ b/src/jalview/datamodel/Alignment.java
@@ -338,15 +338,18 @@ public class Alignment implements AlignmentI
   @Override
   public void deleteSequence(SequenceI s)
   {
-    deleteSequence(findIndex(s));
+    synchronized (sequences)
+    {
+      deleteSequence(findIndex(s));
+    }
   }
 
   @Override
   public void deleteSequence(int i)
   {
-    if (i > -1 && i < getHeight())
+    synchronized (sequences)
     {
-      synchronized (sequences)
+      if (i > -1 && i < getHeight())
       {
         sequences.remove(i);
         hiddenSequences.adjustHeightSequenceDeleted(i);
@@ -357,9 +360,9 @@ public class Alignment implements AlignmentI
   @Override
   public void deleteHiddenSequence(int i)
   {
-    if (i > -1 && i < getHeight())
+    synchronized (sequences)
     {
-      synchronized (sequences)
+      if (i > -1 && i < getHeight())
       {
         sequences.remove(i);
       }
@@ -1008,6 +1011,10 @@ public class Alignment implements AlignmentI
     }
     else if (dataset == null && data != null)
     {
+      if (data == this)
+      {
+        throw new IllegalArgumentException("Circular dataset reference");
+      }
       if (!(data instanceof Alignment))
       {
         throw new Error(