feat: make Shipping Rule Cost Center optional with company default fallback (backport #57355) (#57385)

feat: make Shipping Rule Cost Center optional with company default fallback (#57355)

feat(shipping-rule): make cost center optional with company default fallback

Cost Center on Shipping Rule is no longer mandatory. When left blank, the
applied shipping tax row falls back to the company default cost center,
avoiding the 'Cost Center is required for Profit and Loss account' error on
submit. The rule's project is also applied to the tax row.

(cherry picked from commit a47f25896b)

Co-authored-by: Jatin3128 <140256508+Jatin3128@users.noreply.github.com>

erpnext/accounts/doctype/shipping_rule/shipping_rule.json

@@ -82,8 +82,7 @@
    "fieldname": "cost_center",
    "fieldtype": "Link",
    "label": "Cost Center",
-   "options": "Cost Center",
-   "reqd": 1
+   "options": "Cost Center"
   },
   {
    "fieldname": "shipping_amount_section",
@@ -141,19 +140,20 @@
    "fieldtype": "Column Break"
   },
   {
-    "fieldname": "project",
-    "fieldtype": "Link",
-    "label": "Project",
-    "options": "Project"
+   "fieldname": "project",
+   "fieldtype": "Link",
+   "label": "Project",
+   "options": "Project"
   }
  ],
  "icon": "fa fa-truck",
  "idx": 1,
  "links": [],
- "modified": "2024-03-27 13:10:41.653314",
+ "modified": "2026-07-22 14:53:27.315435",
  "modified_by": "Administrator",
  "module": "Accounts",
  "name": "Shipping Rule",
+ "naming_rule": "By fieldname",
  "owner": "Administrator",
  "permissions": [
   {
@@ -197,7 +197,8 @@
    "write": 1
   }
  ],
+ "row_format": "Dynamic",
  "sort_field": "creation",
  "sort_order": "ASC",
  "states": []
-}
+}

erpnext/accounts/doctype/shipping_rule/shipping_rule.py

@@ -36,18 +36,17 @@ class ShippingRule(Document):
 		from erpnext.accounts.doctype.shipping_rule_condition.shipping_rule_condition import (
 			ShippingRuleCondition,
 		)
-		from erpnext.accounts.doctype.shipping_rule_country.shipping_rule_country import (
-			ShippingRuleCountry,
-		)
+		from erpnext.accounts.doctype.shipping_rule_country.shipping_rule_country import ShippingRuleCountry
 
 		account: DF.Link
 		calculate_based_on: DF.Literal["Fixed", "Net Total", "Net Weight"]
 		company: DF.Link
 		conditions: DF.Table[ShippingRuleCondition]
-		cost_center: DF.Link
+		cost_center: DF.Link | None
 		countries: DF.Table[ShippingRuleCountry]
 		disabled: DF.Check
 		label: DF.Data
+		project: DF.Link | None
 		shipping_amount: DF.Currency
 		shipping_rule_type: DF.Literal["Selling", "Buying"]
 	# end: auto-generated types