Fix regression Product ref not visible

htdocs/comm/propal/class/propal.class.php

@@ -2836,6 +2836,7 @@ class Propal extends CommonObject
                 $this->lines[$i]->description 		= $obj->description;
                 $this->lines[$i]->fk_product		= $obj->fk_product;
                 $this->lines[$i]->ref				= $obj->ref;
+                $this->lines[$i]->product_ref		= $obj->ref;
                 $this->lines[$i]->entity            = $obj->entity;             // Product entity
                 $this->lines[$i]->product_label		= $obj->product_label;
                 $this->lines[$i]->product_desc		= $obj->product_desc;

htdocs/compta/facture/class/facture.class.php

@@ -1125,6 +1125,7 @@ class Facture extends CommonInvoice
 				$line->label            = $objp->custom_label;		// deprecated
 				$line->desc             = $objp->description;		// Description line
 				$line->product_type     = $objp->product_type;		// Type of line
+				$line->ref              = $objp->product_ref;		// Ref product
 				$line->product_ref      = $objp->product_ref;		// Ref product
 				$line->libelle          = $objp->product_label;		// TODO deprecated
 				$line->product_label	= $objp->product_label;		// Label product