Fix locale for authfail to be consistant with g:message FormatTagLib resolveLocale

[codeconsole]

request.locale gets the user's locale, but not the locale set by the user.

g:message gets the locale set by the user and what is used by all the other locations of this plugin.

this fix makes the behavior consistent with the rest of the plugin.

https://github.com/grails/grails-gsp/blob/7ad985676e6217ad331f75aafad8258c1cb9d8cb/grails-plugin-gsp/src/main/groovy/org/grails/plugins/web/taglib/FormatTagLib.groovy#L336-L349

[matrei]

Instead of GrailsWebRequest.lookup().getLocale() ?: Locale.getDefault() I think you could just use LocaleContextHolder.locale which should give you the same result.

[codeconsole]

@matrei "should" ? I took the logic from FormatTagLib.groovy#L336-L349
can you confirm 100% it will give the same result. If so, FormatTagLib would need to be updated as well.

[matrei]

"Should" as in I have not tested it in this context.

According to https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/context/i18n/LocaleContextHolder.html#getLocale():

Return the Locale associated with the current thread, if any, or the system default Locale otherwise

From https://docs.spring.io/spring-framework/reference/web/webmvc/mvc-servlet/localeresolver.html:

When a request comes in, the DispatcherServlet looks for a locale resolver and, if it finds one, it tries to use it to set the locale.

By default in a Grails app, that is a SessionLocaleResolver, set by GrailsI18nPlugin.doWithSpring().

GrailsWebRequest.lookup().getLocale() will eventually end up using the same LocaleResolver to get the Locale but it will not fallback to using the system Locale.