Add support for partitioned cookies

[nosan]

gh-42307

[philwebb]

Thanks @nosan. I think we should also update AbstractServletWebServerFactory.configureSessionCookie and WebSessionIdResolverAutoConfiguration.initializeCookie as well to support the new property. If you have time to update your PR, that would be great. Otherwise we can take it on when we merge.

[nosan]

Thanks for the feedback @philwebb.

I did update my PR but unfortunately, I have not found a straightforward way to update AbstractServletWebServerFactory.configureSessionCookie because jakarta.servlet.SessionCookieConfig does not have a method to set the partitioned property.

The only way as I understand is:

	map.from(cookie::getPartitioned)
				.to(partitioned -> config.setAttribute(PARTITIONED_ATTRIBUTE_NAME, Boolean.toString(partitioned)));

https://jakarta.ee/specifications/servlet/6.0/apidocs/jakarta.servlet/jakarta/servlet/sessioncookieconfig#setAttribute(java.lang.String,java.lang.String)

[bclozel]

I think this is the only way to support partitioned cookies, see Tomcat for reference:

https://github.com/apache/tomcat/blob/d6e5a088433af43a35293f9a2b19cff359efb79b/java/org/apache/catalina/core/ApplicationSessionCookieConfig.java#L224

[nosan]

@bclozel
However, this value could be overridden later through session cookie attributes.

https://github.com/apache/tomcat/blob/d6e5a088433af43a35293f9a2b19cff359efb79b/java/org/apache/catalina/core/ApplicationSessionCookieConfig.java#L229

[bclozel]

@nosan you can raise this as a Tomcat issue if you think this is a bug.

[nosan]

@bclozel
For me, it does not sound like a bug.
As I understood you can set a value for partitioned through Context.setUsePartitioned and then if you specify
sessionCookieConfig.setAttribute(PARTITIONED_ATTRIBUTE_NAME, Boolean.toString(partitioned) this value will be overridden.

// NOTE: The priority order for session cookie configuration is:
// 1. Context level configuration
// 2. Values from SessionCookieConfig
// 3. Defaults

so, this line which I added in this PR should work:

	map.from(cookie::getPartitioned)
   			.to(partitioned -> config.setAttribute(PARTITIONED_ATTRIBUTE_NAME, Boolean.toString(partitioned)));

[bclozel]

That was as well my assessment in the first place.

[mhalbritter]

Thanks @nosan !