// Fixed #PSTEST-501

controllers/admin/AdminProductsController.php

@@ -2356,10 +2356,10 @@ class AdminProductsControllerCore extends AdminController
 					}
 				}
 			// Manage defaut supplier for product
-			if ($new_default_supplier != 0 && $new_default_supplier != $product->id_supplier && Supplier::supplierExists($new_default_supplier))
+			if ($new_default_supplier != $product->id_supplier)
 			{
-				$product->id_supplier = $new_default_supplier;
-				$product->update();
+				$this->object->id_supplier = $new_default_supplier;
+				$this->object->update();
 			}
 		}
 	}

controllers/admin/AdminSupplyOrdersController.php

@@ -300,6 +300,13 @@ class AdminSupplyOrdersControllerCore extends AdminController
 			//specific discount display
 			$this->object->discount_rate = Tools::ps_round($this->object->discount_rate, 4);
 
+			$this->displayInformation(
+				$this->l('Please note that if you wish to order products, they have to be available for the specified Supplier/Warehouse.')
+				.' '.
+				$this->l('See Catalog/Products/Your Product/Suppliers & Warehouses')
+				.'<br />'.
+				$this->l('Also, changing the currency or the supplier will reset the order.')
+			);
 			return parent::renderForm();
 		}
 
@@ -1560,9 +1567,10 @@ class AdminSupplyOrdersControllerCore extends AdminController
 		{
 			$ids = explode('_', $item['id']);
 			$prices = ProductSupplier::getProductSupplierPrice($ids[0], $ids[1], $id_supplier, true);
-			$item['unit_price_te'] = Tools::convertPriceFull($prices['product_supplier_price_te'],
-														     new Currency((int)$prices['id_currency']),
-														     new Currency($id_currency));
+			if (count($prices))
+				$item['unit_price_te'] = Tools::convertPriceFull($prices['product_supplier_price_te'],
+															     new Currency((int)$prices['id_currency']),
+															     new Currency($id_currency));
 		}
 		if ($items)
 			die(Tools::jsonEncode($items));