feat(pos): prevent disabling POS Profile when open POS sessions exist

(cherry picked from commit c5219278fb)

erpnext/accounts/doctype/pos_profile/pos_profile.py

@@ -70,6 +70,7 @@ class POSProfile(Document):
 	# end: auto-generated types
 
 	def validate(self):
+		self.validate_disabled()
 		self.validate_default_profile()
 		self.validate_all_link_fields()
 		self.validate_duplicate_groups()
@@ -94,6 +95,21 @@ class POSProfile(Document):
 					title=_("Mandatory Accounting Dimension"),
 				)
 
+	def validate_disabled(self):
+		old_doc = self.get_doc_before_save()
+
+		if (
+			old_doc
+			and self.disabled
+			and old_doc.disabled != self.disabled
+			and frappe.db.exists("POS Opening Entry", {"pos_profile": self.name, "status": "Open"})
+		):
+			frappe.throw(
+				_("POS Profile {0} cannot be disabled as there are ongoing POS sessions.").format(
+					frappe.bold(self.name)
+				)
+			)
+
 	def validate_default_profile(self):
 		for row in self.applicable_for_users:
 			res = frappe.db.sql(