ICE-4667 involves a code change to UISeries.maximumSeverityAtLeastError(-), which is derived from a Mojarra 1.2 optimisation, where instead of scanning through all the FacesMessages, to determine if a component failed validation, instead we just check the FacesContext.maximumSeverity property.

The problem is, both Mojarra's, and our, code is wrong. Looking at the javadoc for Comparable, we see that:

http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Comparable.html
For the mathematically inclined, the relation that defines the natural ordering on a given class C is:
{(x, y) such that x.compareTo((Object)y) <= 0}.

This means that, when x <= y, x.compareTo(y) <= 0. But if we look at UISeries.maximumSeverityAtLeastError(-), where it's trying to see if FacesMessage.SEVERITY_ERROR <= FacesContext.maximumSeverity, we're using >= 0 instead of <= 0.

FacesMessage.Severity maximumSeverity = facesContext.getMaximumSeverity();
return ( (maximumSeverity != null) && (FacesMessage.SEVERITY_ERROR.compareTo(maximumSeverity) >= 0) );


I've created a bug report with Mojarra, for their equivalent issue in UIData:
https://javaserverfaces.dev.java.net/issues/show_bug.cgi?id=1589