Minicart empty if FPC disabled in Magneto 2.1.1

[ivanweiler]

Preconditions

1. Magento 2.1.1 with sample data
2. Page Cache (FPC) disabled in admin

Steps to reproduce

1. add product to cart
2. switch currency, or switch language, or navigate to login and try to login with invalid user/pass

Expected result

1. product should be in minicart

Actual result

1. mini cart is empty
2. customer can't proceed to checkout

Additional comment

Something is wrong with invalidation of local storage data. Local storage becomes empty and won't refresh when FPC is disabled (possible reason is that private_content_version cookie is missing and js reacts to it).

Funny thing is ..
FPC disabled - customer can't buy, but currency switcher works
FPC enabled - customer can buy, but you can't switch currencies on frontend as reported in #6746

Customers are unable to proceed to checkout and purchase if we need to temporary disable FPC on live site for some reason.

Thx

[Tjitse-E]

I've noticed the same issue, but this was on a Magento 2.1 site.

[ihor-sviziev]

Looks like it's the same issue as #6473.
@ivanweiler could you check if this issue still reproduce after applying my patch from that Pull request?

[sevos1984]

Thanks for reporting, internal ticket created MAGETWO-59955

[erikhansen]

@ihor-sviziev I just tested the patch from your PR and I can verify that it fixed the described issue.

[SantoDE]

Is that possible linked to #4170 @sevos1984 ?

[sidolov]

Hi guys, this issue already fixed in develop branch, commit: 861f596

[ihor-sviziev]

@sidolov I think this issue can't be fixed in this way, because there also issue on client side (JS)

[Dublerq]

Bug still present in 2.1.2. Let's make magento work with cashes! Natively! And tell them to use caches all they long. Who cares about devs