fix: not able to select the item code in work order
diff --git a/erpnext/controllers/queries.py b/erpnext/controllers/queries.py
index 46301b7..638503e 100644
--- a/erpnext/controllers/queries.py
+++ b/erpnext/controllers/queries.py
@@ -204,7 +204,7 @@
 
 	if "description" in searchfields:
 		searchfields.remove("description")
-	
+
 	columns = ''
 	extra_searchfields = [field for field in searchfields
 		if not field in ["name", "item_group", "description"]]
@@ -216,9 +216,10 @@
 		if not field in searchfields]
 	searchfields = " or ".join([field + " like %(txt)s" for field in searchfields])
 
-	if filters.get('supplier'):
-		item_group_list = frappe.get_all('Supplier Item Group', filters = {'supplier': filters.get('supplier')}, fields = ['item_group'])
-		
+	if filters and isinstance(filters, dict) and filters.get('supplier'):
+		item_group_list = frappe.get_all('Supplier Item Group',
+			filters = {'supplier': filters.get('supplier')}, fields = ['item_group'])
+
 		item_groups = []
 		for i in item_group_list:
 			item_groups.append(i.item_group)
@@ -227,7 +228,7 @@
 
 		if item_groups:
 			filters['item_group'] = ['in', item_groups]
-		
+
 	description_cond = ''
 	if frappe.db.count('Item', cache=True) < 50000:
 		# scan description only if items are less than 50000