This is related to 7595. Given: <fmt:message key="mkey" bundle="${application.tBundle}"/> According to section 8.4, page 8-76: "After an action has called ServletResponse.setLocale(), it must determine the character encoding associated with the locale (by calling ServletResponse.getCharacterEncoding()) and store it in the 'javax.servlet.jsp.jstl.fmt.request.charset' session attribute."
Yes, this is related to 7595. Setting the response locale and storing the associated char encoding in the 'javax.servlet.jsp.jstl.fmt.request.charset' session attribute are implemented by the same method (org.apache.taglibs.standard.tag.common.fmt.LocaleSupport.setResponseLocale()). Now that this method gets called as a fix for 7595, it automatically also fixes this (7596) bug.