diff --git a/htdocs/langs/en_US/products.lang b/htdocs/langs/en_US/products.lang
index fd9a823c420..4f3545ae43a 100644
--- a/htdocs/langs/en_US/products.lang
+++ b/htdocs/langs/en_US/products.lang
@@ -380,3 +380,4 @@ ErrorProductCombinationNotFound=Product variant not found
 ActionAvailableOnVariantProductOnly=Action only available on the variant of product
 ProductsPricePerCustomer=Product prices per customers
 ProductSupplierExtraFields=Additional Attributes (Supplier Prices)
+DeleteLinkedProduct=Delete the child product linked to the combination
\ No newline at end of file
diff --git a/htdocs/langs/fr_FR/products.lang b/htdocs/langs/fr_FR/products.lang
index ad22750d1fe..d88b6cab7b9 100644
--- a/htdocs/langs/fr_FR/products.lang
+++ b/htdocs/langs/fr_FR/products.lang
@@ -375,4 +375,4 @@ ErrorDestinationProductNotFound=Produit destination non trouvé
 ErrorProductCombinationNotFound=Variante du produit non trouvé
 ActionAvailableOnVariantProductOnly=Action disponible uniquement sur la variante du produit
 ProductsPricePerCustomer=Prix produit par clients
-ProductSupplierExtraFields=Attributs supplémentaires (Prix fournisseur)
+ProductSupplierExtraFields=Attributs supplémentaires (Prix fournisseur)
\ No newline at end of file
diff --git a/htdocs/product/class/api_products.class.php b/htdocs/product/class/api_products.class.php
index dc4d2e79481..d7d72e28b7c 100644
--- a/htdocs/product/class/api_products.class.php
+++ b/htdocs/product/class/api_products.class.php
@@ -630,6 +630,73 @@ class Products extends DolibarrApi
         );
     }
 
+    /**
+     * Add/Update purchase prices for a product.
+     *
+     * @param   int         $id                             ID of Product
+     * @param  	float		$qty				            Min quantity for which price is valid
+     * @param  	float		$buyprice			            Purchase price for the quantity min
+     * @param  	string		$price_base_type	            HT or TTC
+     * @param  	int		    $fourn_id                       Supplier ID
+     * @param  	int			$availability		            Product availability
+     * @param	string		$ref_fourn			            Supplier ref
+     * @param	float		$tva_tx				            New VAT Rate (For example 8.5. Should not be a string)
+     * @param  	string		$charges			            costs affering to product
+	 * @param  	float		$remise_percent		            Discount  regarding qty (percent)
+	 * @param  	float		$remise				            Discount  regarding qty (amount)
+	 * @param  	int			$newnpr				            Set NPR or not
+	 * @param	int			$delivery_time_days	            Delay in days for delivery (max). May be '' if not defined.
+	 * @param   string      $supplier_reputation            Reputation with this product to the defined supplier (empty, FAVORITE, DONOTORDER)
+     * @param   array		$localtaxes_array	            Array with localtaxes info array('0'=>type1,'1'=>rate1,'2'=>type2,'3'=>rate2) (loaded by getLocalTaxesFromRate(vatrate, 0, ...) function).
+     * @param   string  	$newdefaultvatcode              Default vat code
+     * @param  	float		$multicurrency_buyprice 	    Purchase price for the quantity min in currency
+     * @param  	string		$multicurrency_price_base_type	HT or TTC in currency
+     * @param  	float		$multicurrency_tx	            Rate currency
+     * @param  	string		$multicurrency_code	            Currency code
+     * @param  	string		$desc_fourn     	            Custom description for product_fourn_price
+     * @param  	string		$barcode     	                Barcode
+     * @param  	int		    $fk_barcode_type     	        Barcode type
+     * @return int
+     *
+     * @throws RestException 500
+     * @throws RestException 401
+     *
+     * @url POST {id}/purchase_prices
+     */
+    public function addPurchasePrice($id, $qty, $buyprice, $price_base_type, $fourn_id, $availability, $ref_fourn, $tva_tx, $charges = 0, $remise_percent = 0, $remise = 0, $newnpr = 0, $delivery_time_days = 0, $supplier_reputation = '', $localtaxes_array = array(), $newdefaultvatcode = '', $multicurrency_buyprice = 0, $multicurrency_price_base_type = 'HT', $multicurrency_tx = 1, $multicurrency_code = '', $desc_fourn = '', $barcode = '', $fk_barcode_type = null)
+    {
+        if(! DolibarrApiAccess::$user->rights->produit->creer) {
+            throw new RestException(401);
+        }
+
+        $result = $this->productsupplier->fetch($id);
+        if (!$result) {
+            throw new RestException(404, 'Product not found');
+        }
+
+        if (!DolibarrApi::_checkAccessToResource('product', $this->productsupplier->id)) {
+            throw new RestException(401, 'Access not allowed for login '.DolibarrApiAccess::$user->login);
+        }
+
+        $result = $this->productsupplier->add_fournisseur(DolibarrApiAccess::$user, $fourn_id, $ref_fourn, $qty);
+        if ($result < 0) {
+            throw new RestException(500, "Error adding supplier to product : ".$this->db->lasterror());
+        }
+
+        $fourn = new Fournisseur($this->db);
+        $result = $fourn->fetch($fourn_id);
+        if ($result <= 0) {
+            throw new RestException(404, 'Supplier not found');
+        }
+
+        $result = $this->productsupplier->update_buyprice($qty, $buyprice, DolibarrApiAccess::$user, $price_base_type, $fourn, $availability, $ref_fourn, $tva_tx, $charges, $remise_percent, $remise, $newnpr, $delivery_time_days, $supplier_reputation, $localtaxes_array, $newdefaultvatcode, $multicurrency_buyprice, $multicurrency_price_base_type, $multicurrency_tx, $multicurrency_code, $desc_fourn, $barcode, $fk_barcode_type);
+
+        if ($result <= 0) {
+            throw new RestException(500, "Error updating buy price : ".$this->db->lasterror());
+        }
+        return (int) $this->productsupplier->product_fourn_price_id;
+    }
+
     /**
      * Delete purchase price for a product
      *
@@ -1325,11 +1392,12 @@ class Products extends DolibarrApi
      *
      * "features" is a list of attributes pairs id_attribute=>id_value. Example: array(id_color=>id_Blue, id_size=>id_small, id_option=>id_val_a, ...)
      *
-     * @param  int    $id                       ID of Product
-     * @param  float  $weight_impact            Weight impact of variant
-     * @param  float  $price_impact             Price impact of variant
-     * @param  bool   $price_impact_is_percent  Price impact in percent (true or false)
-     * @param  array  $features                 List of attributes pairs id_attribute->id_value. Example: array(id_color=>id_Blue, id_size=>id_small, id_option=>id_val_a, ...)
+     * @param  int $id ID of Product
+     * @param  float $weight_impact Weight impact of variant
+     * @param  float $price_impact Price impact of variant
+     * @param  bool $price_impact_is_percent Price impact in percent (true or false)
+     * @param  array $features List of attributes pairs id_attribute->id_value. Example: array(id_color=>id_Blue, id_size=>id_small, id_option=>id_val_a, ...)
+     * @param  bool|string $reference Customized reference of variant
      * @return int
      *
      * @throws RestException 500
@@ -1338,7 +1406,7 @@ class Products extends DolibarrApi
      *
      * @url POST {id}/variants
      */
-    public function addVariant($id, $weight_impact, $price_impact, $price_impact_is_percent, $features)
+    public function addVariant($id, $weight_impact, $price_impact, $price_impact_is_percent, $features, $reference = false)
     {
         if (!DolibarrApiAccess::$user->rights->produit->creer) {
             throw new RestException(401);
@@ -1368,17 +1436,13 @@ class Products extends DolibarrApi
         }
 
         $prodcomb = new ProductCombination($this->db);
-        if (!$prodcomb->fetchByProductCombination2ValuePairs($id, $features))
+
+        $result = $prodcomb->createProductCombination(DolibarrApiAccess::$user, $this->product, $features, array(), $price_impact_is_percent, $price_impact, $weight_impact, $reference);
+        if ($result > 0)
         {
-            $result = $prodcomb->createProductCombination(DolibarrApiAccess::$user, $this->product, $features, array(), $price_impact_is_percent, $price_impact, $weight_impact);
-            if ($result > 0)
-            {
-                return $result;
-            } else {
-                throw new RestException(500, "Error creating new product variant");
-            }
+			return $result;
         } else {
-            return $prodcomb->id;
+			throw new RestException(500, "Error creating new product variant");
         }
     }
 
diff --git a/htdocs/variants/class/ProductCombination.class.php b/htdocs/variants/class/ProductCombination.class.php
index 1c09aae62df..fc58d338220 100644
--- a/htdocs/variants/class/ProductCombination.class.php
+++ b/htdocs/variants/class/ProductCombination.class.php
@@ -502,9 +502,10 @@ WHERE c.fk_product_parent = ".(int) $productid." AND p.tosell = 1";
 	 * @param bool $price_var_percent Is the price variation a relative variation?
 	 * @param bool|float $forced_pricevar If the price variation is forced
 	 * @param bool|float $forced_weightvar If the weight variation is forced
+	 * @param bool|string $forced_refvar If the reference is forced
 	 * @return int <0 KO, >0 OK
 	 */
-	public function createProductCombination(User $user, Product $product, array $combinations, array $variations, $price_var_percent = false, $forced_pricevar = false, $forced_weightvar = false)
+	public function createProductCombination(User $user, Product $product, array $combinations, array $variations, $price_var_percent = false, $forced_pricevar = false, $forced_weightvar = false, $forced_refvar = false)
 	{
 		global $db, $conf;
 
@@ -513,7 +514,23 @@ WHERE c.fk_product_parent = ".(int) $productid." AND p.tosell = 1";
 
 		$db->begin();
 
-		$newproduct = clone $product;
+		$forced_refvar = trim($forced_refvar);
+
+		if (!empty($forced_refvar) && $forced_refvar != $product->ref) {
+			$existingProduct = new Product($db);
+			$result = $existingProduct->fetch('', $forced_refvar);
+			if ($result > 0) {
+				$newproduct = $existingProduct;
+			} else {
+				$existingProduct = false;
+				$newproduct = clone $product;
+				$newproduct->ref = $forced_refvar;
+			}
+		} else {
+		    $forced_refvar = false;
+		    $existingProduct = false;
+            $newproduct = clone $product;
+		}
 
 		//Final weight impact
 		$weight_impact = $forced_weightvar;
@@ -536,7 +553,6 @@ WHERE c.fk_product_parent = ".(int) $productid." AND p.tosell = 1";
 			$newcomb = $existingCombination;
 		} else {
 			$newcomb->fk_product_parent = $product->id;
-
 			if ($newcomb->create($user) < 0) {		// Create 1 entry into product_attribute_combination (1 entry for all combinations)
 				$db->rollback();
 				return -1;
@@ -573,10 +589,12 @@ WHERE c.fk_product_parent = ".(int) $productid." AND p.tosell = 1";
 				$price_impact += (float) price2num($variations[$currcombattr][$currcombval]['price']);
 			}
 
-			if (isset($conf->global->PRODUIT_ATTRIBUTES_SEPARATOR)) {
-			    $newproduct->ref .= $conf->global->PRODUIT_ATTRIBUTES_SEPARATOR . $prodattrval->ref;
-			} else {
-			    $newproduct->ref .= '_'.$prodattrval->ref;
+			if ($forced_refvar === false) {
+    			if (isset($conf->global->PRODUIT_ATTRIBUTES_SEPARATOR)) {
+					$newproduct->ref .= $conf->global->PRODUIT_ATTRIBUTES_SEPARATOR . $prodattrval->ref;
+    			} else {
+					$newproduct->ref .= '_'.$prodattrval->ref;
+    			}
 			}
 
 			//The first one should not contain a linebreak
@@ -592,58 +610,65 @@ WHERE c.fk_product_parent = ".(int) $productid." AND p.tosell = 1";
 
 		$newproduct->weight += $weight_impact;
 
-		//To avoid wrong information in price history log
-		$newproduct->price = 0;
-		$newproduct->price_ttc = 0;
-		$newproduct->price_min = 0;
-		$newproduct->price_min_ttc = 0;
-
-		// A new variant must use a new barcode (not same product)
-		$newproduct->barcode = -1;
-
 		// Now create the product
 		//print 'Create prod '.$newproduct->ref.'<br>'."\n";
-		$newprodid = $newproduct->create($user);
-		if ($newprodid < 0)
-		{
-			//In case the error is not related with an already existing product
-			if ($newproduct->error != 'ErrorProductAlreadyExists') {
-			    $this->error[] = $newproduct->error;
-			    $this->errors = $newproduct->errors;
-				$db->rollback();
-				return -1;
-			}
+		if ($existingProduct === false) {
+    		//To avoid wrong information in price history log
+    		$newproduct->price = 0;
+    		$newproduct->price_ttc = 0;
+    		$newproduct->price_min = 0;
+    		$newproduct->price_min_ttc = 0;
 
-			/**
-			 * If there is an existing combination, then we update the prices and weight
-			 * Otherwise, we try adding a random number to the ref
-			 */
+    		// A new variant must use a new barcode (not same product)
+    		$newproduct->barcode = -1;
+		    $result = $newproduct->create($user);
 
-			if ($newcomb->fk_product_child) {
-				$res = $newproduct->fetch($existingCombination->fk_product_child);
-			} else {
-				$orig_prod_ref = $newproduct->ref;
-				$i = 1;
+    		if ($result < 0)
+    		{
+    			//In case the error is not related with an already existing product
+    			if ($newproduct->error != 'ErrorProductAlreadyExists') {
+    			    $this->error[] = $newproduct->error;
+    			    $this->errors = $newproduct->errors;
+    				$db->rollback();
+    				return -1;
+    			}
 
-				do {
-					$newproduct->ref = $orig_prod_ref.$i;
-					$res = $newproduct->create($user);
+    			/**
+    			 * If there is an existing combination, then we update the prices and weight
+    			 * Otherwise, we try adding a random number to the ref
+    			 */
 
-					if ($newproduct->error != 'ErrorProductAlreadyExists') {
-					    $this->errors[] = $newproduct->error;
-						break;
-					}
+    			if ($newcomb->fk_product_child) {
+    				$res = $newproduct->fetch($existingCombination->fk_product_child);
+    			} else {
+    				$orig_prod_ref = $newproduct->ref;
+    				$i = 1;
 
-					$i++;
-				} while ($res < 0);
-			}
+    				do {
+    					$newproduct->ref = $orig_prod_ref.$i;
+    					$res = $newproduct->create($user);
 
-			if ($res < 0) {
-				$db->rollback();
-				return -1;
-			}
+    					if ($newproduct->error != 'ErrorProductAlreadyExists') {
+    					    $this->errors[] = $newproduct->error;
+    						break;
+    					}
 
-			$newproduct->weight += $weight_impact;
+    					$i++;
+    				} while ($res < 0);
+    			}
+
+    			if ($res < 0) {
+    				$db->rollback();
+    				return -1;
+    			}
+    		}
+		} else {
+		    $result = $newproduct->update($newproduct->id, $user);
+		    if ($result < 0)
+		    {
+		        $db->rollback();
+		        return -1;
+		    }
 		}
 
 		$newcomb->fk_product_child = $newproduct->id;
diff --git a/htdocs/variants/combinations.php b/htdocs/variants/combinations.php
index 306586ec504..8c85577c68e 100644
--- a/htdocs/variants/combinations.php
+++ b/htdocs/variants/combinations.php
@@ -33,6 +33,7 @@ $ref = GETPOST('ref', 'alpha');
 $weight_impact = GETPOST('weight_impact', 'alpha');
 $price_impact = GETPOST('price_impact', 'alpha');
 $price_impact_percent = (bool) GETPOST('price_impact_percent');
+$reference = GETPOST('reference', 'alpha');
 $form = new Form($db);
 
 $action = GETPOST('action', 'alpha');
@@ -41,6 +42,7 @@ $show_files = GETPOST('show_files', 'int');
 $confirm = GETPOST('confirm', 'alpha');
 $toselect = GETPOST('toselect', 'array');
 $cancel = GETPOST('cancel', 'alpha');
+$delete_product = GETPOST('delete_product', 'alpha');
 
 // Security check
 $fieldvalue = (!empty($id) ? $id : $ref);
@@ -106,6 +108,10 @@ if ($_POST) {
 		}
 		else
 		{
+			$reference = trim($reference);
+		    if (empty($reference)) {
+		        $reference = false;
+		    }
 			$weight_impact = price2num($weight_impact);
 			$price_impact = price2num($price_impact);
 			$sanit_features = array();
@@ -141,7 +147,7 @@ if ($_POST) {
 
 			if (!$prodcomb->fetchByProductCombination2ValuePairs($id, $sanit_features))
 			{
-				$result = $prodcomb->createProductCombination($user, $object, $sanit_features, array(), $price_impact_percent, $price_impact, $weight_impact);
+				$result = $prodcomb->createProductCombination($user, $object, $sanit_features, array(), $price_impact_percent, $price_impact, $weight_impact, $reference);
 				if ($result > 0)
 				{
 					setEventMessages($langs->trans('RecordSaved'), null, 'mesgs');
@@ -242,7 +248,7 @@ if ($action === 'confirm_deletecombination') {
 	if ($prodcomb->fetch($valueid) > 0) {
 		$db->begin();
 
-		if ($prodcomb->delete($user) > 0 && $prodstatic->fetch($prodcomb->fk_product_child) > 0 && $prodstatic->delete($user) > 0) {
+		if ($prodcomb->delete($user) > 0 && (empty($delete_product) || ($delete_product == 'on' && $prodstatic->fetch($prodcomb->fk_product_child) > 0 && $prodstatic->delete($user) > 0))) {
 			$db->commit();
 			setEventMessages($langs->trans('RecordSaved'), null, 'mesgs');
 			header('Location: '.dol_buildpath('/variants/combinations.php?id='.$object->id, 2));
@@ -590,6 +596,10 @@ if (!empty($id) || !empty($ref))
 				<td>
 				</td>
 			</tr>
+			<tr>
+				<td><label for="reference"><?php echo $langs->trans('Reference') ?></label></td>
+				<td><input type="text" id="reference" name="reference" value="<?php echo trim($reference) ?>"></td>
+			</tr>
 			<tr>
 				<td><label for="price_impact"><?php echo $langs->trans('PriceImpact') ?></label></td>
 				<td><input type="text" id="price_impact" name="price_impact" value="<?php echo price($price_impact) ?>">
@@ -629,7 +639,7 @@ if (!empty($id) || !empty($ref))
 					$langs->trans('Delete'),
 					$langs->trans('ProductCombinationDeleteDialog', $prodstatic->ref),
 					"confirm_deletecombination",
-					'',
+					array(array('label'=> $langs->trans('DeleteLinkedProduct'),'type'=> 'checkbox', 'name' => 'delete_product', 'value' => false)),
 					0,
 					1
 				);