The EL 3.0 has some changes in it that break javax.faces.INTERPRET_STRING_AS_NULL. This is detailed here [0] under the section 'EL 3.0 (2013-current)'. To get around the issue, the page introduces the class EmptyToNullStringELResolver that needs to be installed in the application.
Should the documentation for the JSF 2.2 web context parameter javax.faces.INTERPRET_STRING_AS_NULL [1] be updated since it no longer works with EL 3.0 out-of-the-box? [0] http://balusc.omnifaces.org/2015/10/the-empty-string-madness.html [1] https://myfaces.apache.org/core22/myfaces-impl/webconfig.html#javax_faces_INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL
