Showing primefaces overlay panel leads to NPE in Mojarra code - jsf-2

Question

I use a p:overlayPanel on several places. It offers values from which the user can choose. This overlay panel is parameterized and used on several places. Therefore I show the panel with a click on a button like this:
<p:commandButton oncomplete="PF('overlayPanelVar').loadContents('#{component.clientId}');" immediate="true" actionListener="#{myController.setSelectedObject(curMaskElement, curDummyCssClass)}" process="#this" />
This works but only in one case I get a NullPointerException in JSF implementation mojarra this commandButton was created inside ui:repeat.
When the user clicks on the button it works and overlay panel appears, but if a value is chosen from the overlay panel (which is a link) this happens:
15:16:30,873 SEVERE [org.primefaces.application.exceptionhandler.PrimeExceptionHandler] (http-/0.0.0.0:9090-5) null: java.lang.NullPointerException
at com.sun.faces.facelets.component.UIRepeat.restoreChildState(UIRepeat.java:433) [jsf-impl-2.2.12.jar:2.2.12]
at com.sun.faces.facelets.component.UIRepeat.restoreChildState(UIRepeat.java:448) [jsf-impl-2.2.12.jar:2.2.12]
at com.sun.faces.facelets.component.UIRepeat.restoreChildState(UIRepeat.java:415) [jsf-impl-2.2.12.jar:2.2.12]
at com.sun.faces.facelets.component.UIRepeat.setIndex(UIRepeat.java:546) [jsf-impl-2.2.12.jar:2.2.12]
at com.sun.faces.facelets.component.UIRepeat.invokeOnComponent(UIRepeat.java:695) [jsf-impl-2.2.12.jar:2.2.12]
at javax.faces.component.UIComponent.invokeOnComponent(UIComponent.java:1503) [jsf-api-2.2.12.jar:2.2]
at javax.faces.component.UIComponentBase.invokeOnComponent(UIComponentBase.java:714) [jsf-api-2.2.12.jar:2.2]
at javax.faces.component.UIComponent.invokeOnComponent(UIComponent.java:1503) [jsf-api-2.2.12.jar:2.2]
at javax.faces.component.UIComponentBase.invokeOnComponent(UIComponentBase.java:714) [jsf-api-2.2.12.jar:2.2]
at com.sun.faces.facelets.component.UIRepeat.invokeOnComponent(UIRepeat.java:697) [jsf-impl-2.2.12.jar:2.2.12]
The code in mojarra UIReapeat.class:
private void restoreChildState(FacesContext faces, UIComponent c) {
// reset id
String id = c.getId();
c.setId(id);
// hack
if (c instanceof EditableValueHolder) {
EditableValueHolder evh = (EditableValueHolder) c;
String clientId = c.getClientId(faces);
SavedState ss = this.getChildState().get(clientId);
if (ss != null) {
ss.apply(evh);
} else {
String childId = clientId.substring(initialClientId.length() + 1);
childId = childId.substring(childId.indexOf(getSeparatorChar(faces)) + 1);
childId = initialClientId + getSeparatorChar(faces) + childId;
if (initialChildState.containsKey(childId)) {
SavedState initialState = initialChildState.get(childId);
initialState.apply(evh);
} else {
NullState.apply(evh);
}
}
}
// continue hack
Iterator itr = c.getFacetsAndChildren();
while (itr.hasNext()) {
restoreChildState(faces, (UIComponent) itr.next());
}
}
The initialClientId member is null.
This appears with version 2.2.12.
If I change the JSF implementation of JBoss 6.2 to bundled which comes with JBoss this exception does not occur. The jars are jboss-jsf-api_2.1_spec-2.1.19.1.Final-redhat-1.jar and jsf-impl-2.1.19-redhat-2.jar.
In another usage of the overlay panel I create the commandButton inside a h:dataTable iteration and it works.
This is probably a mojarra bug?
The NPE occurs when the commandButton is created like this:
<p:panelGrid styleClass="searchMaskFieldsGrid">
<ui:repeat value="#{curSearch.getSearchMaskDescription().getRows()}" var="curRow" varStatus="rowStatus">
<p:row styleClass="searchMaskRow">
<ui:repeat value="#{curRow.elements}" var="curMaskElement" varStatus="colStatus">
<p:column colspan="#{curMaskElement.columnSpan}"
styleClass="#{curMaskElement.isLabel() ? 'searchMaskLabelColumn' : 'searchMaskInputColumn'}">
<!-- this includes one field and here can be the commandButton be added -->
<ui:include src="/sections/search/searchFields.xhtml">
<ui:param name="curMaskElement" value="#{curMaskElement}" />
<ui:param name="curRowIndex" value="#{rowStatus.index}" />
<ui:param name="curColumnIndex" value="#{colStatus.index}" />
</ui:include>
</p:column>
</ui:repeat>
<ui:param name="unfilledColumnsCount" value="#{searchBL.determinedUnfilledColumns(curSearch.getSearchMaskDescription(), curRow)}" />
<p:column colspan="#{unfilledColumnsCount}" rendered="#{unfilledColumnsCount gt 0}">
<h:outputLabel value="" />
</p:column>
</p:row>
</ui:repeat>
</p:panelGrid>
Is it maybe a known limitation with PF('overlayPanelVar').loadContents('#{component.clientId}'); and ui:repeat and someone knows a workaround?