From 177cc1c330f3cc0626156e3cf3f6d7f00d2d906c Mon Sep 17 00:00:00 2001
From: Benjamin Dauvergne <bdauvergne@entrouvert.com>
Date: Mon, 25 Jan 2021 14:23:09 +0100
Subject: [PATCH] misc: add migration to fix absence of immutable_unaccent()
 (#50462)

---
 .../0033_recreate_immutable_unaccent.py       | 76 +++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 src/authentic2/migrations/0033_recreate_immutable_unaccent.py

diff --git a/src/authentic2/migrations/0033_recreate_immutable_unaccent.py b/src/authentic2/migrations/0033_recreate_immutable_unaccent.py
new file mode 100644
index 00000000..798a58cf
--- /dev/null
+++ b/src/authentic2/migrations/0033_recreate_immutable_unaccent.py
@@ -0,0 +1,76 @@
+# Generated by Django 2.2.17 on 2021-01-25 13:21
+
+from __future__ import unicode_literals
+
+from django.db import migrations, transaction
+from django.db.migrations.operations.base import Operation
+from django.db.utils import InternalError, OperationalError, ProgrammingError
+
+
+class SafeExtensionOperation(Operation):
+    reversible = True
+
+    def state_forwards(self, app_label, state):
+        pass
+
+    def database_forwards(self, app_label, schema_editor, from_state, to_state):
+        if schema_editor.connection.vendor != 'postgresql':
+            return
+        try:
+            with transaction.atomic():
+                try:
+                    schema_editor.execute('CREATE EXTENSION IF NOT EXISTS %s SCHEMA public' % self.name)
+                except (OperationalError, ProgrammingError):
+                    # OperationalError if the extension is not available
+                    # ProgrammingError in case of denied permission
+                    RunSQLIfExtension.extensions_installed = False
+        except InternalError:
+            # InternalError (current transaction is aborted, commands ignored
+            # until end of transaction block) would be raised when django-
+            # tenant-schemas set search_path.
+            RunSQLIfExtension.extensions_installed = False
+
+    def database_backwards(self, app_label, schema_editor, from_state, to_state):
+        try:
+            with transaction.atomic():
+                schema_editor.execute('DROP EXTENSION IF EXISTS %s' % self.name)
+        except InternalError:
+            # Raised when other objects depend on the extension. This happens in a multitenant
+            # context, where extension in installed in schema "public" but referenced in others (via
+            # public.gist_trgm_ops). In this case, do nothing, as the query should be successful
+            # when last tenant is processed.
+            pass
+
+
+class RunSQLIfExtension(migrations.RunSQL):
+    extensions_installed = True
+
+    def __getattribute__(self, name):
+        if name == 'sql' and not self.extensions_installed:
+            return migrations.RunSQL.noop
+        return object.__getattribute__(self, name)
+
+
+class UnaccentExtension(SafeExtensionOperation):
+    name = 'unaccent'
+
+
+class TrigramExtension(SafeExtensionOperation):
+    name = 'pg_trgm'
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('authentic2', '0032_initialize_search_vectors'),
+    ]
+
+    operations = [
+        TrigramExtension(),
+        UnaccentExtension(),
+        RunSQLIfExtension(
+            sql=["CREATE OR REPLACE FUNCTION public.immutable_unaccent(text) RETURNS varchar AS $$ "
+                 "SELECT public.unaccent('public.unaccent',$1::text); $$ LANGUAGE 'sql' IMMUTABLE"],
+            reverse_sql=['DROP FUNCTION IF EXISTS public.immutable_unaccent(text)']
+        ),
+    ]
-- 
2.29.2