Fix Grid header merging on init (#9688)

Fixes #9686

2 files changed, 7 insertions, 1 deletions

diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/ColumnConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/ColumnConnector.java
index c47488f78e..7ac6c518ad 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/ColumnConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/ColumnConnector.java
@@ -20,6 +20,7 @@ import com.vaadin.client.annotations.OnStateChange;
 import com.vaadin.client.connectors.AbstractRendererConnector;
 import com.vaadin.client.extensions.AbstractExtensionConnector;
 import com.vaadin.client.widgets.Grid.Column;
+import com.vaadin.client.widgets.Grid.HeaderCell;
 import com.vaadin.shared.data.DataCommunicatorConstants;
 import com.vaadin.shared.ui.Connect;
 import com.vaadin.shared.ui.grid.ColumnState;
@@ -48,6 +49,11 @@ public class ColumnConnector extends AbstractExtensionConnector {
         public String getConnectorId() {
             return connectorId;
         }
+
+        @Override
+        protected void setDefaultHeaderContent(HeaderCell cell) {
+            // NO-OP, Server takes care of header contents.
+        }
     }
 
     private CustomColumn column;
diff --git a/client/src/main/java/com/vaadin/client/widgets/Grid.java b/client/src/main/java/com/vaadin/client/widgets/Grid.java
index 45937e0c07..9a5674e86e 100755
--- a/client/src/main/java/com/vaadin/client/widgets/Grid.java
+++ b/client/src/main/java/com/vaadin/client/widgets/Grid.java
@@ -4853,7 +4853,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
         private void updateHeader() {
             HeaderRow row = grid.getHeader().getDefaultRow();
             if (row != null) {
-                row.getCell(this).setText(headerCaption);
+                setDefaultHeaderContent(row.getCell(this));
                 if (isHidable()) {
                     grid.columnHider.updateHidingToggle(this);
                 }