null pointer exception bug fix

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index a7ba035..4f102ad 100755 (executable)
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -633,7 +633,7 @@ public class SeqCanvas extends JComponent
       int blockStart = startRes;
       int blockEnd = endRes;
 
-      for (int i = 0; i < regions.size(); i++)
+      for (int i = 0; regions!=null && i < regions.size(); i++)
       {
         int[] region = (int[]) regions.elementAt(i);
         int hideStart = region[0];