Interaction with portals/prerendering

[jakearchibald]

It seems pretty natural that an entry's view of forward session history will change over time. However, portals/prerendering creates a situation where a the view of backwards session history changes.

While prerendered, the page would (presumably) not have access to previous session history entries of the parent page, but once it activates it will.

Should there be a way to access the previous state while prerendering? Should there be an event when backwards history state changes?

This might be an issue for history built in stages #17.

[domenic]

This was discussed a bit in https://bugs.chromium.org/p/chromium/issues/detail?id=1212819. Note that history will only extend backward if we resolve #71 by doing no-BCG-scoping. (Which I think is correct.)

I don't think giving prerendered pages insight into their referrer's navigation API history entry list is a good idea. But maybe an event when you start growing entries backward in that way is a good idea.