Merge branch 'develop' into refactor/buying/reports
diff --git a/erpnext/stock/doctype/item/item.py b/erpnext/stock/doctype/item/item.py
index c8bb1b9..20bc9d9 100644
--- a/erpnext/stock/doctype/item/item.py
+++ b/erpnext/stock/doctype/item/item.py
@@ -232,10 +232,10 @@
 
 	def clear_retain_sample(self):
 		if not self.has_batch_no:
-			self.retain_sample = None
+			self.retain_sample = False
 
 		if not self.retain_sample:
-			self.sample_quantity = None
+			self.sample_quantity = 0
 
 	def add_default_uom_in_conversion_factor_table(self):
 		if not self.is_new() and self.has_value_changed("stock_uom"):
diff --git a/erpnext/stock/doctype/item/test_item.py b/erpnext/stock/doctype/item/test_item.py
index e35c8bf..0c710b0 100644
--- a/erpnext/stock/doctype/item/test_item.py
+++ b/erpnext/stock/doctype/item/test_item.py
@@ -717,8 +717,8 @@
 
 		item.has_batch_no = None
 		item.save()
-		self.assertEqual(item.retain_sample, None)
-		self.assertEqual(item.sample_quantity, None)
+		self.assertEqual(item.retain_sample, False)
+		self.assertEqual(item.sample_quantity, 0)
 		item.delete()
 
 	def consume_item_code_with_differet_stock_transactions(