ID duplication in pubprovided ids module

[JulianRSL]

Type of issue

BUG

Description

Duplicated ids are added to a pubprovided IDs on every auction if identity module that provides id with the same source is present and has ids

Steps to reproduce

1.Define configuration to a pubprovided Ids module to provide 'adserver.org' (TDID) id:

function myf(){
return [
    {
        "uids": [
            {
                "ext": {
                    "stype": "ppuid"
                },
                "id": "4a958e6e-de2c-45f1-bd66-836890a2e78a"
            }
        ],
        "source": "adserver.org"
    }
]
}

pbjs.setConfig({
     userSync: {
         userIds: [{
             name: "pubProvidedId",
             params: {
                 eidsFunction: myf   // any function that exists in the page
             }
         }]
     }
 });

2.Configure unified ids module to provide id:

pbjs.setConfig({
     userSync: {
         userIds: [{
             name: "unifiedId",
             value: {"tdid": "D6885E90-2A7A-4E0F-87CB-7734ED1B99A3"}
         }]
     }
 });

3.Run an auction

Test page

https://jsfiddle.net/6te4Ly81/

Expected results

After running any amount of auctions amount of ids in pubprovided supposed to be the same if no additional configuration was added.

JSON value of pubprovidedId : '[{"uids":[{"ext":{"stype":"ppuid"},"id":"4a958e6e-de2c-45f1-bd66-836890a2e78a"}],"source":"adserver.org"}]'

(could be simulated on a page by selecting prebid 8.14)

Actual results

Additional ids added to pubprovided ids list (duplications from ids provided by identity module)
JSON value for pubProvidedId: '[{"uids":[{"ext":{"stype":"ppuid"},"id":"4a958e6e-de2c-45f1-bd66-836890a2e78a"},{"id":"XXXXXXXX-XXXX-XXXX-XXXX-7734ED1B99A3","atype":1,"ext":{"rtiPartner":"TDID"}},{"id":"XXXXXXXX-XXXX-XXXX-XXXX-7734ED1B99A3","atype":1,"ext":{"rtiPartner":"TDID"}},{"id":"XXXXXXXX-XXXX-XXXX-XXXX-7734ED1B99A3","atype":1,"ext":{"rtiPartner":"TDID"}},{"id":"XXXXXXXX-XXXX-XXXX-XXXX-7734ED1B99A3","atype":1,"ext":{"rtiPartner":"TDID"}}],"source":"adserver.org"}]'

(could be simulated on a page by selecting prebid 8.15)

Platform details

Prebid.js version >= 8.15

Other information

Suspected to be related to :
425cf20

Case study:
Prebid bug introduced starting version 8 15.pdf

[patmmccann]

Can you please hash out expected and actual results with jsons

[JulianRSL]

Added to a bug description