Fixed NPE in Tabsheet (#10479)

Change-Id: If1b5def25a463cfa4449ed476161a54a39f0770a

diff --git a/client/src/com/vaadin/client/ui/VTabsheet.java b/client/src/com/vaadin/client/ui/VTabsheet.java
index 6d3f2365e263bd0938467ceadf7a3080bcc70359..e39742b2fabca7788087be81f91828f073ea3049 100644 (file)
--- a/client/src/com/vaadin/client/ui/VTabsheet.java
+++ b/client/src/com/vaadin/client/ui/VTabsheet.java
@@ -748,7 +748,7 @@ public class VTabsheet extends VTabsheetBase implements Focusable,
         // style inheritance)
         if (ComponentStateUtil.hasStyles(state)) {
             final List<String> styles = state.styles;
-            if (!currentStyle.equals(styles.toString())) {
+            if (currentStyle == null || !currentStyle.equals(styles.toString())) {
                 currentStyle = styles.toString();
                 final String tabsBaseClass = TABS_CLASSNAME;
                 String tabsClass = tabsBaseClass;