diff --git a/htdocs/variants/class/ProductCombination.class.php b/htdocs/variants/class/ProductCombination.class.php
index 0e8f69958dc..215536ac43a 100644
--- a/htdocs/variants/class/ProductCombination.class.php
+++ b/htdocs/variants/class/ProductCombination.class.php
@@ -281,7 +281,9 @@ class ProductCombination
 	{
 		global $conf;
 
-		$sql = "SELECT rowid, fk_product_parent, fk_product_child, variation_price, variation_price_percentage, variation_weight FROM ".MAIN_DB_PREFIX."product_attribute_combination WHERE fk_product_parent = ".((int) $fk_product_parent)." AND entity IN (".getEntity('product').")";
+		$sql = "SELECT rowid, fk_product_parent, fk_product_child, variation_price, variation_price_percentage, variation_ref_ext, variation_weight";
+		$sql.= " FROM ".MAIN_DB_PREFIX."product_attribute_combination";
+		$sql.= " WHERE fk_product_parent = ".((int) $fk_product_parent)." AND entity IN (".getEntity('product').")";
 
 		$query = $this->db->query($sql);
 
@@ -489,10 +491,10 @@ class ProductCombination
 		$child->price_autogen = $parent->price_autogen;
 		$child->weight = $parent->weight;
 		// Only when Parent Status are updated
-		if ($parent->oldcopy && ($parent->status != $parent->oldcopy->status)) {
+		if (!empty($parent->oldcopy) && ($parent->status != $parent->oldcopy->status)) {
 			$child->status = $parent->status;
 		}
-		if ($parent->oldcopy && ($parent->status_buy != $parent->oldcopy->status_buy)) {
+		if (!empty($parent->oldcopy) && ($parent->status_buy != $parent->oldcopy->status_buy)) {
 			$child->status_buy = $parent->status_buy;
 		}
 
diff --git a/htdocs/variants/combinations.php b/htdocs/variants/combinations.php
index b6ffd948bd6..f01e674c44a 100644
--- a/htdocs/variants/combinations.php
+++ b/htdocs/variants/combinations.php
@@ -69,7 +69,7 @@ if ($id > 0 || $ref) {
 	$object->fetch($id, $ref);
 }
 
-$selectedvariant = !empty($_SESSION['addvariant_'.$object->id]) ? $_SESSION['addvariant_'.$object->id] : 0;
+$selectedvariant = !empty($_SESSION['addvariant_'.$object->id]) ? $_SESSION['addvariant_'.$object->id] : array();
 
 // Security check
 if (empty($conf->variants->enabled)) {
@@ -154,7 +154,7 @@ if (($action == 'add' || $action == 'create') && empty($massaction) && !GETPOST(
 		$price_impact = price2num($price_impact);
 
 		// for conf PRODUIT_MULTIPRICES
-		if ($conf->global->PRODUIT_MULTIPRICES) {
+		if (!empty($conf->global->PRODUIT_MULTIPRICES)) {
 			$level_price_impact = array_map('price2num', $level_price_impact);
 		} else {
 			$level_price_impact = array(1 => $price_impact);
@@ -279,7 +279,7 @@ if (($action == 'add' || $action == 'create') && empty($massaction) && !GETPOST(
 	$prodcomb->variation_weight = price2num($weight_impact);
 
 	// for conf PRODUIT_MULTIPRICES
-	if ($conf->global->PRODUIT_MULTIPRICES) {
+	if (!empty($conf->global->PRODUIT_MULTIPRICES)) {
 		$level_price_impact = array_map('price2num', $level_price_impact);
 
 		$prodcomb->variation_price = $level_price_impact[1];
@@ -292,7 +292,7 @@ if (($action == 'add' || $action == 'create') && empty($massaction) && !GETPOST(
 		$prodcomb->variation_price_percentage = $price_impact_percent;
 	}
 
-	if ($conf->global->PRODUIT_MULTIPRICES) {
+	if (!empty($conf->global->PRODUIT_MULTIPRICES)) {
 		$prodcomb->combination_price_levels = array();
 		for ($i = 1; $i <= $conf->global->PRODUIT_MULTIPRICES_LIMIT; $i++) {
 			$productCombinationLevel = new ProductCombinationLevel($db);