Recently I fixed a TCK failure in Liferay Faces Bridge regarding ExternalContext.getRequestContentType():
http://issues.liferay.com/browse/FACES-1226

The method used to return "text/html" but with the FACES-1226 it returns "multipart/form-data; ..." and this is changing the behavior of the following method in FileEntryResourceHandler:

{code}
    @Override
    public boolean isResourceRequest(FacesContext facesContext) {
        ExternalContext externalContext = facesContext.getExternalContext();
        String reqContentType = externalContext.getRequestContentType();
        
        if ( (null == reqContentType) ||
                !reqContentType.startsWith("multipart") ) {
            return wrapped.isResourceRequest(facesContext);
        }
{code}

Because of this, ace:fileEntry is causing the following stacktrace:

21:05:14,993 ERROR [ExceptionHandlerAjaxImpl:57]
java.lang.NullPointerException
at org.icefaces.apache.commons.fileupload.servlet.ServletFileUpload.isMultipartContent(ServletFileUpload.java:68)
at org.icefaces.ace.component.fileentry.FileEntryPhaseListener.beforePhase(FileEntryPhaseListener.java:114)
at com.sun.faces.lifecycle.Phase.handleBeforePhase(Phase.java:228)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:99)
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:116)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at com.liferay.faces.bridge.BridgePhaseResourceImpl.execute(BridgePhaseResourceImpl.java:109)