[Feature] Provision to allow unlink the payment against the invoice

erpnext/accounts/doctype/accounts_settings/accounts_settings.json

@@ -10,6 +10,7 @@
  "doctype": "DocType", 
  "document_type": "Other", 
  "editable_grid": 1, 
+ "engine": "InnoDB", 
  "fields": [
   {
    "allow_on_submit": 0, 
@@ -194,6 +195,32 @@
    "search_index": 0, 
    "set_only_once": 0, 
    "unique": 0
+  }, 
+  {
+   "allow_on_submit": 0, 
+   "bold": 0, 
+   "collapsible": 0, 
+   "columns": 0, 
+   "fieldname": "unlink_payment_on_cancellation_of_invoice", 
+   "fieldtype": "Check", 
+   "hidden": 0, 
+   "ignore_user_permissions": 0, 
+   "ignore_xss_filter": 0, 
+   "in_filter": 0, 
+   "in_list_view": 0, 
+   "label": "Unlink Payment on Cancellation of Invoice", 
+   "length": 0, 
+   "no_copy": 0, 
+   "permlevel": 0, 
+   "precision": "", 
+   "print_hide": 0, 
+   "print_hide_if_no_value": 0, 
+   "read_only": 0, 
+   "report_hide": 0, 
+   "reqd": 0, 
+   "search_index": 0, 
+   "set_only_once": 0, 
+   "unique": 0
   }
  ], 
  "hide_heading": 0, 
@@ -207,8 +234,8 @@
  "issingle": 1, 
  "istable": 0, 
  "max_attachments": 0, 
- "modified": "2016-10-05 16:13:10.978208", 
+ "modified": "2016-10-19 16:37:11.664552", 
- "modified_by": "rohitw1991@gmail.com", 
+ "modified_by": "Administrator", 
  "module": "Accounts", 
  "name": "Accounts Settings", 
  "owner": "Administrator", 

erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py

@@ -578,6 +578,7 @@ class PurchaseInvoice(BuyingController):
 
 		if not self.is_return:
 			from erpnext.accounts.utils import unlink_ref_doc_from_payment_entries
+			if frappe.db.get_single_value('Accounts Settings', 'unlink_payment_on_cancellation_of_invoice'):
 				unlink_ref_doc_from_payment_entries(self.doctype, self.name)
 
 			self.update_prevdoc_status()

erpnext/accounts/doctype/sales_invoice/sales_invoice.py

@@ -136,6 +136,7 @@ class SalesInvoice(SellingController):
 		self.check_close_sales_order("sales_order")
 
 		from erpnext.accounts.utils import unlink_ref_doc_from_payment_entries
+		if frappe.db.get_single_value('Accounts Settings', 'unlink_payment_on_cancellation_of_invoice'):
 			unlink_ref_doc_from_payment_entries(self.doctype, self.name)
 
 		if self.is_return:

erpnext/docs/user/manual/en/accounts/setup/accounts-settings.md

@@ -7,4 +7,8 @@
 
 * Credit Controller: Role that is allowed to submit transactions that exceed credit limits set.
 
+* Make Payment via Journal Entry: If checked, on invoice if uer has clicked on payment system open the journal entry else payment entry
+
+* Unlink Payment on Cancellation of Invoice: If checked system inlink the payment against the invoice else shows the link error.
+
 {next}