Fixed #34050 -- Replaced invalid chars in migration names with '_'.

Thanks to Bishal Gautam for the report and initial implementation.

Regression in fa58450a9a.

Co-Authored-By: Bishal Gautam <bisalgt@gmail.com>

django/db/migrations/migration.py

@@ -1,3 +1,5 @@
+import re
+
 from django.db.migrations.utils import get_migration_name_timestamp
 from django.db.transaction import atomic
 
@@ -205,7 +207,7 @@ class Migration:
             return "initial"
 
         raw_fragments = [op.migration_name_fragment for op in self.operations]
-        fragments = [name for name in raw_fragments if name]
+        fragments = [re.sub(r"\W+", "_", name) for name in raw_fragments if name]
 
         if not fragments or len(fragments) != len(self.operations):
             return "auto_%s" % get_migration_name_timestamp()

tests/migrations/test_autodetector.py

@@ -5314,6 +5314,20 @@ class MigrationSuggestNameTests(SimpleTestCase):
         migration = Migration("some_migration", "test_app")
         self.assertIs(migration.suggest_name().startswith("auto_"), True)
 
+    def test_operation_with_invalid_chars_in_suggested_name(self):
+        class Migration(migrations.Migration):
+            operations = [
+                migrations.AddConstraint(
+                    "Person",
+                    models.UniqueConstraint(
+                        fields=["name"], name="person.name-*~unique!"
+                    ),
+                ),
+            ]
+
+        migration = Migration("some_migration", "test_app")
+        self.assertEqual(migration.suggest_name(), "person_person_name_unique_")
+
     def test_none_name(self):
         class Migration(migrations.Migration):
             operations = [migrations.RunSQL("SELECT 1 FROM person;")]