ToolTipManager may be for popup menu item, so then ancestor window may

hansonr · hansonr · commit ad04ed049a84 · 2019-07-10T11:57:16.000+01:00
be null
diff --git a/sources/net.sf.j2s.java.core/src/javax/swing/ToolTipManager.java b/sources/net.sf.j2s.java.core/src/javax/swing/ToolTipManager.java
@@ -272,7 +272,8 @@ void showTipWindow() {
 		if (insideComponent == null || !insideComponent.isShowing())
 			return;
 		Component win = insideComponent.getTopLevelAncestor();
-		if (win.isWindowOrJSApplet()) {
+		// will be null for some menu items
+		if (win != null  && win.isWindowOrJSApplet()) {
 			if (((Window) win).getModalBlocker() != null)
 				return;
 		}
