1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
require_relative '../../lib/mastodon/migration_warning'
class FixAccountsUniqueIndex < ActiveRecord::Migration[5.2]
include Mastodon::MigrationWarning
class Account < ApplicationRecord
# Dummy class, to make migration possible across version changes
has_one :user, inverse_of: :account
def local?
domain.nil?
end
def acct
local? ? username : "#{username}@#{domain}"
end
end
class StreamEntry < ApplicationRecord
# Dummy class, to make migration possible across version changes
belongs_to :account, inverse_of: :stream_entries
end
class Status < ApplicationRecord
# Dummy class, to make migration possible across version changes
belongs_to :account
end
class Mention < ApplicationRecord
# Dummy class, to make migration possible across version changes
belongs_to :account
end
class StatusPin < ApplicationRecord
# Dummy class, to make migration possible across version changes
belongs_to :account
end
disable_ddl_transaction!
def up
migration_duration_warning(<<~EXPLANATION)
This migration will irreversibly delete user accounts with duplicate
usernames. You may use the `rake mastodon:maintenance:find_duplicate_usernames`
task to manually deal with such accounts before running this migration.
EXPLANATION
duplicates = Account.connection.select_all('SELECT string_agg(id::text, \',\') AS ids FROM accounts GROUP BY lower(username), lower(domain) HAVING count(*) > 1').to_ary
duplicates.each do |row|
deduplicate_account!(row['ids'].split(','))
end
remove_index :accounts, name: 'index_accounts_on_username_and_domain_lower' if index_name_exists?(:accounts, 'index_accounts_on_username_and_domain_lower')
safety_assured { execute 'CREATE UNIQUE INDEX CONCURRENTLY index_accounts_on_username_and_domain_lower ON accounts (lower(username), lower(domain))' }
remove_index :accounts, name: 'index_accounts_on_username_and_domain' if index_name_exists?(:accounts, 'index_accounts_on_username_and_domain')
end
def down
raise ActiveRecord::IrreversibleMigration
end
private
def deduplicate_account!(account_ids)
accounts = Account.where(id: account_ids).to_a
accounts = accounts.first.local? ? accounts.sort_by(&:created_at) : accounts.sort_by(&:updated_at).reverse
reference_account = accounts.shift
say_with_time "Deduplicating @#{reference_account.acct} (#{accounts.size} duplicates)..." do
accounts.each do |other_account|
if other_account.public_key == reference_account.public_key
# The accounts definitely point to the same resource, so
# it's safe to re-attribute content and relationships
merge_accounts!(reference_account, other_account)
elsif other_account.local?
# Since domain is in the GROUP BY clause, both accounts
# are always either going to be local or not local, so only
# one check is needed. Since we cannot support two users with
# the same username locally, one has to go. 😢
other_account.user&.destroy
end
other_account.destroy
end
end
end
def merge_accounts!(main_account, duplicate_account)
[Status, Mention, StatusPin, StreamEntry].each do |klass|
klass.where(account_id: duplicate_account.id).in_batches.update_all(account_id: main_account.id)
end
# Since it's the same remote resource, the remote resource likely
# already believes we are following/blocking, so it's safe to
# re-attribute the relationships too. However, during the presence
# of the index bug users could have *also* followed the reference
# account already, therefore mass update will not work and we need
# to check for (and skip past) uniqueness errors
[Favourite, Follow, FollowRequest, Block, Mute].each do |klass|
klass.where(account_id: duplicate_account.id).find_each do |record|
record.update_attribute(:account_id, main_account.id)
rescue ActiveRecord::RecordNotUnique
next
end
end
[Follow, FollowRequest, Block, Mute].each do |klass|
klass.where(target_account_id: duplicate_account.id).find_each do |record|
record.update_attribute(:target_account_id, main_account.id)
rescue ActiveRecord::RecordNotUnique
next
end
end
end
end
|
