From 291d95dcc3cd85050421d2ab022e01a6d89c0f3d Mon Sep 17 00:00:00 2001
From: Roman Chvanikov <chvanikoff@pm.me>
Date: Wed, 3 Jul 2019 01:14:40 +0300
Subject: [PATCH 1/2] Fix migration

---
 .../migrations/20170522160642_case_insensivtivity.exs  | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/priv/repo/migrations/20170522160642_case_insensivtivity.exs b/priv/repo/migrations/20170522160642_case_insensivtivity.exs
index c7565946e..470a545e5 100644
--- a/priv/repo/migrations/20170522160642_case_insensivtivity.exs
+++ b/priv/repo/migrations/20170522160642_case_insensivtivity.exs
@@ -2,18 +2,24 @@ defmodule Pleroma.Repo.Migrations.CaseInsensivtivity do
   use Ecto.Migration
 
   def up do
-    execute ("create extension if not exists citext")
+    execute("create extension if not exists citext")
+
+    drop_if_exists(index(:users, [:email]))
+
     alter table(:users) do
-      modify :email, :citext
-      modify :nickname, :citext
+      modify(:email, :citext)
+      modify(:nickname, :citext)
     end
+
+    create_if_not_exists(index(:users, [:email]))
   end
 
   def down do
     alter table(:users) do
-      modify :email, :string
-      modify :nickname, :string
+      modify(:email, :string)
+      modify(:nickname, :string)
     end
-    execute ("drop extension if exists citext")
+
+    execute("drop extension if exists citext")
   end
 end

From efefee82415d872209cf5884375891e577f54781 Mon Sep 17 00:00:00 2001
From: Roman Chvanikov <chvanikoff@pm.me>
Date: Wed, 3 Jul 2019 14:56:02 +0300
Subject: [PATCH 2/2] Split alters rather than work with indexes

---
 .../repo/migrations/20170522160642_case_insensivtivity.exs | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/priv/repo/migrations/20170522160642_case_insensivtivity.exs b/priv/repo/migrations/20170522160642_case_insensivtivity.exs
index 470a545e5..9a67727e9 100644
--- a/priv/repo/migrations/20170522160642_case_insensivtivity.exs
+++ b/priv/repo/migrations/20170522160642_case_insensivtivity.exs
@@ -1,22 +1,28 @@
 defmodule Pleroma.Repo.Migrations.CaseInsensivtivity do
   use Ecto.Migration
 
+  # Two-steps alters are intentional.
+  # When alter of 2 columns is done in a single operation,
+  # inconsistent failures happen because of index on `email` column.
+
   def up do
     execute("create extension if not exists citext")
 
-    drop_if_exists(index(:users, [:email]))
-
     alter table(:users) do
       modify(:email, :citext)
-      modify(:nickname, :citext)
     end
 
-    create_if_not_exists(index(:users, [:email]))
+    alter table(:users) do
+      modify(:nickname, :citext)
+    end
   end
 
   def down do
     alter table(:users) do
       modify(:email, :string)
+    end
+
+    alter table(:users) do
       modify(:nickname, :string)
     end