diff -r 56cd8111b7f7 -r 41300fa6a67c src/tools/uic/customwidgetsinfo.cpp
--- a/src/tools/uic/customwidgetsinfo.cpp	Tue Jan 26 12:42:25 2010 +0200
+++ b/src/tools/uic/customwidgetsinfo.cpp	Tue Feb 02 00:43:10 2010 +0200
@@ -88,6 +88,14 @@
     return false;
 }
 
+bool CustomWidgetsInfo::isCustomWidgetContainer(const QString &className) const
+{
+    if (const DomCustomWidget *dcw = m_customWidgets.value(className, 0))
+        if (dcw->hasElementContainer())
+            return dcw->elementContainer() != 0;
+    return false;
+}
+
 QString CustomWidgetsInfo::realClassName(const QString &className) const
 {
     if (className == QLatin1String("Line"))