Prolog

The ResponseCacheStrategy::update() method makes all responses uncacheable if one of the embedded responses is not cacheable:

Note that $this->cacheable is never set to true again.

Current behavior

This together with #18164 prevents the main response from being cached by the client if there is an embedded response. My web page is delivered with must-revalidate, no-cache, private although I have specified max-age: 1800.

Expected behavior

I would have expected the main response (the web page) to be cacheable by the client (max-age=1800, …). Is this the intended behavior or is it a bug?