[#1112] Preserving `id` on user insert conflict on order not to violate conversation_partipations_user_id_fkey constraint.

CHANGELOG.md

@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Mastodon API: Embedded relationships not being properly rendered in the Account entity of Status entity
 - Mastodon API: Add `account_id`, `type`, `offset`, and `limit` to search API (`/api/v1/search` and `/api/v2/search`)
 - ActivityPub C2S: follower/following collection pages being inaccessible even when authentifucated if `hide_followers`/ `hide_follows` was set
+- Existing user id not being preserved on insert conflict
 
 ### Added
 - MRF: Support for priming the mediaproxy cache (`Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy`)

lib/pleroma/user.ex

@@ -1211,7 +1211,7 @@ defmodule Pleroma.User do
     data
     |> Map.put(:name, blank?(data[:name]) || data[:nickname])
     |> remote_user_creation()
-    |> Repo.insert(on_conflict: :replace_all, conflict_target: :nickname)
+    |> Repo.insert(on_conflict: :replace_all_except_primary_key, conflict_target: :nickname)
     |> set_cache()
   end