JAL-4134 tree panel shouldn’t try to redraw before tree is calculated..

diff --git a/src/jalview/gui/TreeCanvas.java b/src/jalview/gui/TreeCanvas.java
index 7bdb673..354feac 100755 (executable)
--- a/src/jalview/gui/TreeCanvas.java
+++ b/src/jalview/gui/TreeCanvas.java
@@ -719,6 +719,7 @@ public class TreeCanvas extends JPanel implements MouseListener, Runnable,
     if (longestName == null || tree == null)
     {
       g2.drawString("Calculating tree.", 20, 20);
+      return;
     }
     offy = font.getSize() + 10;