Merge branch 'dev'

common/models/Document.php

                                         } else {
                                                 $productOrderMatch = false;
                                                 foreach ($productsOrdersArray[$productOrder->id_product] as &$theProductOrder) {
-                                                        if ($theProductOrder->unit == $productOrder->unit && $theProductOrder->price == $productOrder->price) {
+                                                        if ($theProductOrder->unit == $productOrder->unit
+                                                                && ($theProductOrder->price == $productOrder->price
+                                                                        || ($this->isInvoicePrice()
+                                                                                && $theProductOrder->invoice_price == $productOrder->invoice_price))) {
                                                                 $theProductOrder->quantity += $productOrder->quantity;
                                                                 $productOrderMatch = true;
                                                         }