It occurs to me there are 2 separate actions we are interested in

1. select a bunch of contacts & find all the matches for them (based on either

default rule or selecting a rule).

2. dedupe the contacts selected against each other.

I have submitted a patch to add the former (simpler technically) option to (Find duplicates for these contacts)
that uses the default rule to find all matches for selected contacts. This is the simpler
option of those listed. Implementing 2 will require some more work on the cacheKey mechanism
since we are trying to by-pass the rules.

Note I just put this on staging but testing there it needs some further tweaking.

Ok - working on staging now - search for a contact where you know there are duplicate emails, select the contact & choose 'Find duplicates for these contacts' and it will render email-based matches for you to work through. Per comments above this is one of 2 interpretations of this requirement (the easier one)

This is on staging now & seems to work ok - eg. search for 'McNaughton' & select all & choose 'Find duplicates for these contacts' - you can then go into the first pair & progress through the others

Change 375720 had a related patch set uploaded (by Eileen; owner: Eileen):
[wikimedia/fundraising/crm/civicrm@master] Follow patch from QA on find duplicates task

https://gerrit.wikimedia.org/r/375720

Change 375721 had a related patch set uploaded (by Eileen; owner: Eileen):
[wikimedia/fundraising/crm/civicrm@master] Fix spelling error.

https://gerrit.wikimedia.org/r/375721

Change 375720 merged by jenkins-bot:
[wikimedia/fundraising/crm/civicrm@master] Follow patch from QA on find duplicates task

https://gerrit.wikimedia.org/r/375720

Change 375721 merged by jenkins-bot:
[wikimedia/fundraising/crm/civicrm@master] Fix spelling error.

https://gerrit.wikimedia.org/r/375721