Fix payroll scheduled change row locking

backend/finance/payroll/scheduled_changes.py

@@ -52,7 +52,7 @@ def materialize_scheduled_changes(
         component.code: component for component in get_payroll_components(target_period)
     }
     source_lines = list(
-        PayrollInputLine.objects.select_for_update()
+        PayrollInputLine.objects.select_for_update(of=("self",))
         .select_related("created_by", "approved_by")
         .filter(
             period=source_period,

backend/tests/finance/test_payroll_scheduled_changes.py

@@ -237,6 +237,40 @@ def test_marker_waits_until_the_next_period_is_created(scheduled_workspace):
     assert len(row["applied_scheduled_changes"]) == 1
 
 
+def test_materialization_locks_only_payroll_input_lines(
+    scheduled_workspace,
+    monkeypatch,
+):
+    from django.db.models import QuerySet
+
+    lock_targets = []
+    original_select_for_update = QuerySet.select_for_update
+
+    def track_select_for_update(queryset, *args, **kwargs):
+        if queryset.model is PayrollInputLine:
+            lock_targets.append(kwargs.get("of"))
+        return original_select_for_update(queryset, *args, **kwargs)
+
+    monkeypatch.setattr(QuerySet, "select_for_update", track_select_for_update)
+
+    workspace = scheduled_workspace
+    component = create_scheduled_component(
+        workspace["client"],
+        name="Маркер с безопасной блокировкой",
+        source_period=workspace["periods"][7],
+    )
+    response = set_cell(
+        workspace["client"],
+        period=workspace["periods"][7],
+        employee=workspace["employee"],
+        component_code=component["code"],
+        amount="500.00",
+    )
+
+    assert response.status_code == 201, response.content
+    assert ("self",) in lock_targets
+
+
 def test_closed_next_period_rejects_marker_value(scheduled_workspace):
     workspace = scheduled_workspace
     target = workspace["periods"][8]