Problem with multiple identities on Gerrit

[Mike Kaganski]

Hello!

Currently I have a gerrit account with two identities: 
mikekaganski at hotmail.com (using openid provider 
http://pip.verisignlabs.com/) and mike.kaganski at collabora.com.

Since linking the second identity some time ago, several times I 
mistakingly used openid provider in the form 
https://pip.verisignlabs.com/ (note the https vs http). The system 
successfully logged me in, but then I discovered that those were two 
different accounts.

Some days ago I discovered that now gerrit supports new OAuth2, and 
tried to link another identity (google) to my account 
(https://gerrit.libreoffice.org/#/settings/web-identities). I got 
results identical to described here: 
http://nabble.documentfoundation.org/Multiple-identities-on-Gerrit-td4068367.html. 
But somehow, I was able to finally login to my account that turned out 
to be unchanged (no new google identity).

Today I received a notification from Verisign Labs (openid provider) 
stating that they will discontinue their service starting from 12 
September 2016. So being unable to link another identity is an issue for me.

Could someone provide some guidance what steps should I follow to solve 
the two small issues I desccribed:

1. To join two existing accounts (mikekaganski at hotmail.com using 
http://pip.verisignlabs.com/ and https://pip.verisignlabs.com/) into one 
that is currently linked with mike.kaganski at collabora.com?

2. To link new google identity mikekaganski at gmail.com to that account 
using OAuth2? (it seems that the new identity is already linked to some 
*third* account.)

Thank you!

-- 
Best regards,
Mike Kaganski