Opera 9 cookie bug

This bug affects:

Steps to reproduce:

  1. Subscribe to this page RSS feed (of course in Opera and not some external app).
  2. Click the link in the feed
  3. Check the results below which are different depending on from where you open this page.

Actual testcase:

Expected results:
You should see green message above which means that cookie was invalidated by setting it with past date.

What actually happens:
Green message when opening this page standard way (typing address, following link from other page), and red message when opening this page from newsfeed, mail etc.

Some more info:
You can see that cookie is not being deleted when opening this page from feed window. This is a bug that I called "Past date cookie does not invalidate cookie".
This also affects widgets and it has been reported by me (when I though that it's a widget only bug) a long time ago:
#213361 | Past date cookie does not invalidate cookie - testcase widget

Bonus bug:

Go to Site Preferences, change some irrelevant setting and hit ok.

Result:
Cookies are disabled for this domain when opening this page from newsfeed. And I mean no cookie support at all! ZERO! (GMail will throw 'Cookies Disabled' error when trying to open mail from atom feed).

This is a bit different issue to the one above, contrary to what you might think

Cookie test:

This was also first reported by me as a widget bug:
#213362 | Site Preferences blocks incoming cookies - testcase widget