Fix empty TreeGrid (#9067)

1 files changed, 7 insertions, 1 deletions

diff --git a/client/src/main/java/com/vaadin/client/connectors/treegrid/TreeGridConnector.java b/client/src/main/java/com/vaadin/client/connectors/treegrid/TreeGridConnector.java
index 72c4487aaf..b5c11eba1d 100644
--- a/client/src/main/java/com/vaadin/client/connectors/treegrid/TreeGridConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/treegrid/TreeGridConnector.java
@@ -98,7 +98,8 @@ public class TreeGridConnector extends GridConnector {
             // Id of new hierarchy column. Choose first when nothing explicitly
             // set
             String newHierarchyColumnId = getState().hierarchyColumnId;
-            if (newHierarchyColumnId == null) {
+            if (newHierarchyColumnId == null
+                    && !getState().columnOrder.isEmpty()) {
                 newHierarchyColumnId = getState().columnOrder.get(0);
             }
 
@@ -106,6 +107,11 @@ public class TreeGridConnector extends GridConnector {
             Grid.Column<?, ?> newColumn = getColumn(newHierarchyColumnId);
             Grid.Column<?, ?> oldColumn = getColumn(oldHierarchyColumnId);
 
+            if (newColumn == null && oldColumn == null) {
+                // No hierarchy column defined
+                return;
+            }
+
             // Unwrap renderer of old column
             if (oldColumn != null
                     && oldColumn.getRenderer() instanceof HierarchyRenderer) {