fix: Maintenance Schedule child table status for legacy data (#27554)

* fix: Maintenance Schedule child table status for legacy data

* fix: Include legacy draft schedules in patch

* fix: Pre-commit formatting
diff --git a/erpnext/maintenance/doctype/maintenance_schedule_detail/maintenance_schedule_detail.json b/erpnext/maintenance/doctype/maintenance_schedule_detail/maintenance_schedule_detail.json
index 8ccef6a..afe273f 100644
--- a/erpnext/maintenance/doctype/maintenance_schedule_detail/maintenance_schedule_detail.json
+++ b/erpnext/maintenance/doctype/maintenance_schedule_detail/maintenance_schedule_detail.json
@@ -89,13 +89,14 @@
    "width": "160px"
   },
   {
+   "allow_on_submit": 1,
    "columns": 2,
+   "default": "Pending",
    "fieldname": "completion_status",
    "fieldtype": "Select",
    "in_list_view": 1,
    "label": "Completion Status",
-   "options": "Pending\nPartially Completed\nFully Completed",
-   "read_only": 1
+   "options": "Pending\nPartially Completed\nFully Completed"
   },
   {
    "fieldname": "column_break_3",
@@ -125,10 +126,11 @@
  "idx": 1,
  "istable": 1,
  "links": [],
- "modified": "2021-05-27 16:07:25.905015",
+ "modified": "2021-09-16 21:25:22.506485",
  "modified_by": "Administrator",
  "module": "Maintenance",
  "name": "Maintenance Schedule Detail",
+ "naming_rule": "Random",
  "owner": "Administrator",
  "permissions": [],
  "sort_field": "modified",
diff --git a/erpnext/patches/v13_0/set_status_in_maintenance_schedule_table.py b/erpnext/patches/v13_0/set_status_in_maintenance_schedule_table.py
new file mode 100644
index 0000000..bf6285d
--- /dev/null
+++ b/erpnext/patches/v13_0/set_status_in_maintenance_schedule_table.py
@@ -0,0 +1,9 @@
+import frappe
+
+
+def execute():
+	frappe.db.sql("""
+		UPDATE `tabMaintenance Schedule Detail`
+		SET completion_status = 'Pending'
+		WHERE docstatus < 2
+	""")