Merge pull request #5375 from rohitwaghchaure/editable_fields_overriding_issue

[Fixes] material request's editable fields overriding with purchase common
diff --git a/erpnext/buying/doctype/purchase_common/purchase_common.js b/erpnext/buying/doctype/purchase_common/purchase_common.js
index d101ece..dbfda21 100644
--- a/erpnext/buying/doctype/purchase_common/purchase_common.js
+++ b/erpnext/buying/doctype/purchase_common/purchase_common.js
@@ -12,12 +12,14 @@
 erpnext.buying.BuyingController = erpnext.TransactionController.extend({
 	setup: function() {
 		this._super();
-		this.frm.get_field('items').grid.editable_fields = [
-			{fieldname: 'item_code', columns: 4},
-			{fieldname: 'qty', columns: 2},
-			{fieldname: 'rate', columns: 3},
-			{fieldname: 'amount', columns: 2}
-		];
+		if(!this.frm.get_field('items').grid.editable_fields){
+			this.frm.get_field('items').grid.editable_fields = [
+				{fieldname: 'item_code', columns: 4},
+				{fieldname: 'qty', columns: 2},
+				{fieldname: 'rate', columns: 3},
+				{fieldname: 'amount', columns: 2}
+			];
+		}
 	},
 
 	onload: function() {