An invalid remember-me cookie should throw a RememberMeAuthenticationException

Summary

If an invalid remember-me token is provided by a counterfeit cookie, an IllegalArgumentException is thrown:

java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - Error at index 1 in: "3J"
	at java.base/java.net.URLDecoder.decode(URLDecoder.java:232) ~[na:na]
	at java.base/java.net.URLDecoder.decode(URLDecoder.java:142) ~[na:na]
	at org.springframework.security.web.authentication.rememberme.AbstractRememberMeServices.decodeCookie(AbstractRememberMeServices.java:242) ~[spring-security-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.security.web.authentication.rememberme.AbstractRememberMeServices.autoLogin(AbstractRememberMeServices.java:135) ~[spring-security-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:98) ~[spring-security-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	

Expected Behavior

A RememberMeAuthenticationException is thrown.

Version

spring-security-web-5.1.5.RELEASE.jar:5.1.5.RELEASE

Start in org.springframework.security.web.authentication.rememberme.AbstractRememberMeServices, particularly decodeCookie and its caller autoLogin, following the stack trace from the invalid cookie. Reproduce the malformed token and verify that the observed IllegalArgumentException is replaced by the expected RememberMeAuthenticationException.