[fix] unset default customer group (#10689)

* [fix] unset default customer group

* added __init__.py file for patch v8.9 directory
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 7ec2753..31ecd29 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -434,4 +434,5 @@
 erpnext.patches.v8_5.remove_project_type_property_setter
 erpnext.patches.v8_7.add_more_gst_fields
 erpnext.patches.v8_7.fix_purchase_receipt_status
-erpnext.patches.v8_6.rename_bom_update_tool
\ No newline at end of file
+erpnext.patches.v8_6.rename_bom_update_tool
+erpnext.patches.v8_9.set_default_customer_group
diff --git a/erpnext/patches/v8_9/__init__.py b/erpnext/patches/v8_9/__init__.py
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/erpnext/patches/v8_9/__init__.py
@@ -0,0 +1 @@
+
diff --git a/erpnext/patches/v8_9/set_default_customer_group.py b/erpnext/patches/v8_9/set_default_customer_group.py
new file mode 100644
index 0000000..b121998
--- /dev/null
+++ b/erpnext/patches/v8_9/set_default_customer_group.py
@@ -0,0 +1,6 @@
+import frappe
+
+def execute():
+	selling_settings = frappe.get_single('Selling Settings')
+	selling_settings.set_default_customer_group_and_territory()
+	selling_settings.save()
diff --git a/erpnext/selling/doctype/selling_settings/selling_settings.py b/erpnext/selling/doctype/selling_settings/selling_settings.py
index ee7d203..d297883 100644
--- a/erpnext/selling/doctype/selling_settings/selling_settings.py
+++ b/erpnext/selling/doctype/selling_settings/selling_settings.py
@@ -8,6 +8,7 @@
 import frappe.defaults
 from frappe.utils import cint
 from frappe.custom.doctype.property_setter.property_setter import make_property_setter
+from frappe.utils.nestedset import get_root_of
 
 from frappe.model.document import Document
 
@@ -31,3 +32,9 @@
 		for doctype in ("Sales Order", "Sales Invoice", "Delivery Note"):
 			make_property_setter(doctype, "tax_id", "hidden", self.hide_tax_id, "Check")
 			make_property_setter(doctype, "tax_id", "print_hide", self.hide_tax_id, "Check")
+
+	def set_default_customer_group_and_territory(self):
+		if not self.customer_group:
+			self.customer_group = get_root_of('Customer Group')
+		if not self.territory:
+			self.territory = get_root_of('Territory')
diff --git a/erpnext/setup/setup_wizard/setup_wizard.py b/erpnext/setup/setup_wizard/setup_wizard.py
index 4dec3d7..c40ad55 100644
--- a/erpnext/setup/setup_wizard/setup_wizard.py
+++ b/erpnext/setup/setup_wizard/setup_wizard.py
@@ -176,6 +176,7 @@
 	selling_settings.so_required = "No"
 	selling_settings.dn_required = "No"
 	selling_settings.allow_multiple_items = 1
+	selling_settings.set_default_customer_group_and_territory()
 	selling_settings.save()
 
 	buying_settings = frappe.get_doc("Buying Settings")
diff --git a/erpnext/startup/boot.py b/erpnext/startup/boot.py
index 6b503b3..3164306 100644
--- a/erpnext/startup/boot.py
+++ b/erpnext/startup/boot.py
@@ -4,7 +4,6 @@
 
 from __future__ import unicode_literals
 import frappe
-from frappe.utils.nestedset import get_root_of
 
 def boot_session(bootinfo):
 	"""boot session - send website info if guest"""
@@ -17,9 +16,9 @@
 
 		load_country_and_currency(bootinfo)
 		bootinfo.sysdefaults.territory = frappe.db.get_single_value('Selling Settings',
-			'territory') or get_root_of('Territory')
+			'territory')
 		bootinfo.sysdefaults.customer_group = frappe.db.get_single_value('Selling Settings',
-			'customer_group') or get_root_of('Customer Group')
+			'customer_group')
 
 		bootinfo.notification_settings = frappe.get_doc("Notification Control",
 			"Notification Control")