JAL-3878 Fix null pointer exception when preparing empty sequences for job.

diff --git a/src/jalview/ws2/operations/AlignmentOperation.java b/src/jalview/ws2/operations/AlignmentOperation.java
index 14564d6..530ea24 100644 (file)
--- a/src/jalview/ws2/operations/AlignmentOperation.java
+++ b/src/jalview/ws2/operations/AlignmentOperation.java
@@ -789,8 +789,8 @@ public class AlignmentOperation implements Operation
         }
         else
         {
-          String seqString = null;
-          if (seq.getEnd() >= seq.getStart()) // is it ever false?
+          String seqString = "";
+          if (seq.getEnd() >= seq.getStart())  // true if gaps only
           {
             seqString = seq.getSequenceAsString();
             if (!submitGaps)