diff --git a/htdocs/fourn/class/fournisseur.commande.class.php b/htdocs/fourn/class/fournisseur.commande.class.php
index cb7d0ce6e6f..f8c57d7cc94 100644
--- a/htdocs/fourn/class/fournisseur.commande.class.php
+++ b/htdocs/fourn/class/fournisseur.commande.class.php
@@ -1126,7 +1126,7 @@ class CommandeFournisseur extends CommonOrder
 	            // insert products details into database
 	            for ($i=0;$i<$num;$i++)
 	            {
-	                $result = $this->addline(
+	                $result = $this->addline(              // This include test on qty if option SUPPLIERORDER_WITH_NOPRICEDEFINED is not set
 	                    $this->lines[$i]->desc,
 	                    $this->lines[$i]->subprice,
 	                    $this->lines[$i]->qty,
@@ -1306,11 +1306,11 @@ class CommandeFournisseur extends CommonOrder
      */
 	function addline($desc, $pu_ht, $qty, $txtva, $txlocaltax1=0.0, $txlocaltax2=0.0, $fk_product=0, $fk_prod_fourn_price=0, $fourn_ref='', $remise_percent=0.0, $price_base_type='HT', $pu_ttc=0.0, $type=0, $info_bits=0, $notrigger=false, $date_start=null, $date_end=null, $array_options=0, $fk_unit=null)
     {
-        global $langs,$mysoc, $conf;
+        global $langs,$mysoc,$conf;
 
         $error = 0;
 
-        dol_syslog(get_class($this)."::addline $desc, $pu_ht, $qty, $txtva, $txlocaltax1, $txlocaltax2. $fk_product, $fk_prod_fourn_price, $fourn_ref, $remise_percent, $price_base_type, $pu_ttc, $type, $fk_unit");
+        dol_syslog(get_class($this)."::addline $desc, $pu_ht, $qty, $txtva, $txlocaltax1, $txlocaltax2, $fk_product, $fk_prod_fourn_price, $fourn_ref, $remise_percent, $price_base_type, $pu_ttc, $type, $fk_unit");
         include_once DOL_DOCUMENT_ROOT.'/core/lib/price.lib.php';
 
         // Clean parameters
@@ -1350,40 +1350,45 @@ class CommandeFournisseur extends CommonOrder
         {
             $this->db->begin();
 
-            if ($fk_prod_fourn_price > 0)
+            if ($fk_product > 0)
             {
-                $prod = new Product($this->db, $fk_product);
-                if ($prod->fetch($fk_product) > 0)
+                if (empty($conf->global->SUPPLIERORDER_WITH_NOPRICEDEFINED))
                 {
-                    $result=$prod->get_buyprice($fk_prod_fourn_price,$qty,$fk_product,$fourn_ref);
-                    if ($result > 0)
+                    // Check quantity is enough
+                    dol_syslog(get_class($this)."::addline we check supplier prices fk_product=".$fk_product." fk_prod_fourn_price=".$fk_prod_fourn_price." qty=".$qty." fourn_ref=".$fourn_ref);
+                    $prod = new Product($this->db, $fk_product);
+                    if ($prod->fetch($fk_product) > 0)
                     {
-                        $label = $prod->libelle;
-                        $pu    = $prod->fourn_pu;
-                        $ref   = $prod->ref_fourn;
-                        $product_type = $prod->type;
+                        $result=$prod->get_buyprice($fk_prod_fourn_price, $qty, $fk_product, $fourn_ref);   // Search on couple $fk_prod_fourn_price/$qty first, then on triplet $qty/$fk_product/$fourn_ref
+                        if ($result > 0)
+                        {
+                            $label = $prod->libelle;
+                            $pu    = $prod->fourn_pu;
+                            $ref   = $prod->ref_fourn;
+                            $product_type = $prod->type;
+                        }
+                        if ($result == 0 || $result == -1)
+                        {
+                            $langs->load("errors");
+                            $this->error = "Ref " . $prod->ref . " " . $langs->trans("ErrorQtyTooLowForThisSupplier");
+                            $this->db->rollback();
+                            dol_syslog(get_class($this)."::addline result=".$result." - ".$this->error, LOG_DEBUG);
+                            return -1;
+                        }
+                        if ($result < -1)
+                        {
+                            $this->error=$prod->error;
+                            $this->db->rollback();
+                            dol_syslog(get_class($this)."::addline result=".$result." - ".$this->error, LOG_ERR);
+                            return -1;
+                        }
                     }
-                    if ($result == 0 || $result == -1)
-                    {
-                        $langs->load("errors");
-                        $this->error = "Ref " . $prod->ref . " " . $langs->trans("ErrorQtyTooLowForThisSupplier");
-                        $this->db->rollback();
-                        dol_syslog(get_class($this)."::addline result=".$result." - ".$this->error, LOG_DEBUG);
-                        return -1;
-                    }
-                    if ($result < -1)
-                    {
+                    else
+    				{
                         $this->error=$prod->error;
-                        $this->db->rollback();
-                        dol_syslog(get_class($this)."::addline result=".$result." - ".$this->error, LOG_ERR);
                         return -1;
                     }
                 }
-                else
-				{
-                    $this->error=$prod->error;
-                    return -1;
-                }
             }
             else
             {
@@ -1449,7 +1454,6 @@ class CommandeFournisseur extends CommonOrder
 			$sql.= ", ".$multicurrency_total_ttc;
             $sql.= ")";
 
-            dol_syslog(get_class($this)."::addline", LOG_DEBUG);
             $resql=$this->db->query($sql);
             //print $sql;
             if ($resql)
diff --git a/htdocs/fourn/class/fournisseur.product.class.php b/htdocs/fourn/class/fournisseur.product.class.php
index 48896689dce..05024f9991a 100644
--- a/htdocs/fourn/class/fournisseur.product.class.php
+++ b/htdocs/fourn/class/fournisseur.product.class.php
@@ -216,7 +216,7 @@ class ProductFournisseur extends Product
 
         $this->db->begin();
 
-        if ($this->product_fourn_price_id)
+        if ($this->product_fourn_price_id > 0)
         {
 	  		$sql = "UPDATE ".MAIN_DB_PREFIX."product_fournisseur_price";
 			$sql.= " SET fk_user = " . $user->id." ,";
@@ -237,7 +237,7 @@ class ProductFournisseur extends Product
 			$sql.= " WHERE rowid = ".$this->product_fourn_price_id;
 			// TODO Add price_base_type and price_ttc
 
-			dol_syslog(get_class($this).'::update_buyprice', LOG_DEBUG);
+			dol_syslog(get_class($this).'::update_buyprice update knowing id of line = product_fourn_price_id = '.$this->product_fourn_price_id, LOG_DEBUG);
 			$resql = $this->db->query($sql);
 			if ($resql)
 			{
@@ -249,7 +249,7 @@ class ProductFournisseur extends Product
 				if (empty($error))
 				{
 					$this->db->commit();
-					return 0;
+					return $this->product_fourn_price_id;
 				}
 				else
 				{
@@ -267,94 +267,88 @@ class ProductFournisseur extends Product
 
         else
         {
-	        	// Delete price for this quantity
-	        	$sql = "DELETE FROM  ".MAIN_DB_PREFIX."product_fournisseur_price";
-          		$sql.= " WHERE fk_soc = ".$fourn->id." AND ref_fourn = '".$this->db->escape($ref_fourn)."' AND quantity = ".$qty." AND entity = ".$conf->entity;
-				dol_syslog(get_class($this).'::update_buyprice', LOG_DEBUG);
-	        	$resql=$this->db->query($sql);
-				if ($resql)
-		  		{
-		            // Add price for this quantity to supplier
-		            $sql = "INSERT INTO ".MAIN_DB_PREFIX."product_fournisseur_price(";
-		            $sql.= "datec, fk_product, fk_soc, ref_fourn, fk_user, price, quantity, remise_percent, remise, unitprice, tva_tx, charges, unitcharges, fk_availability, info_bits, entity, delivery_time_days,supplier_reputation)";
-		            $sql.= " values('".$this->db->idate($now)."',";
-		            $sql.= " ".$this->id.",";
-		            $sql.= " ".$fourn->id.",";
-		            $sql.= " '".$this->db->escape($ref_fourn)."',";
-		            $sql.= " ".$user->id.",";
-		            $sql.= " ".$buyprice.",";
-		            $sql.= " ".$qty.",";
-					$sql.= " ".$remise_percent.",";
-					$sql.= " ".$remise.",";
-		            $sql.= " ".$unitBuyPrice.",";
-		            $sql.= " ".$tva_tx.",";
-		            $sql.= " ".$charges.",";
-		            $sql.= " ".$unitCharges.",";
-		            $sql.= " ".$availability.",";
-		            $sql.= " ".$newnpr.",";
-		            $sql.= $conf->entity.",";
-		            $sql.= $delivery_time_days.",";
-			    $sql.= (empty($supplier_reputation) ? 'NULL' :  "'".$this->db->escape($supplier_reputation)."'");
-			    $sql.=")";
-
-		            dol_syslog(get_class($this)."::update_buyprice", LOG_DEBUG);
-		            if (! $this->db->query($sql))
-		            {
-		                $error++;
-		            }
-
-		            if (! $error  && !empty($conf->global->PRODUCT_PRICE_SUPPLIER_NO_LOG))
-		            {
-		                // Add record into log table
-		                $sql = "INSERT INTO ".MAIN_DB_PREFIX."product_fournisseur_price_log(";
-		                $sql.= "datec, fk_product_fournisseur,fk_user,price,quantity)";
-		                $sql.= "values('".$this->db->idate($now)."',";
-		                $sql.= " ".$this->product_fourn_id.",";
-		                $sql.= " ".$user->id.",";
-		                $sql.= " ".price2num($buyprice).",";
-		                $sql.= " ".$qty;
-		                $sql.=")";
-
-		                $resql=$this->db->query($sql);
-		                if (! $resql)
-		                {
-		                    $error++;
-		                }
-		            }
-
-
-		            if (! $error)
-		            {
-                        // Call trigger
-                        $result=$this->call_trigger('SUPPLIER_PRODUCT_BUYPRICE_CREATE',$user);
-                        if ($result < 0) $error++;
+            dol_syslog(get_class($this) . '::update_buyprice without knowing id of line, so we delete from company, quantity and supplier_ref and insert again', LOG_DEBUG);
+            
+            // Delete price for this quantity
+            $sql = "DELETE FROM  " . MAIN_DB_PREFIX . "product_fournisseur_price";
+            $sql .= " WHERE fk_soc = " . $fourn->id . " AND ref_fourn = '" . $this->db->escape($ref_fourn) . "' AND quantity = " . $qty . " AND entity = " . $conf->entity;
+            $resql = $this->db->query($sql);
+            if ($resql) {
+                // Add price for this quantity to supplier
+                $sql = "INSERT INTO " . MAIN_DB_PREFIX . "product_fournisseur_price(";
+                $sql .= "datec, fk_product, fk_soc, ref_fourn, fk_user, price, quantity, remise_percent, remise, unitprice, tva_tx, charges, unitcharges, fk_availability, info_bits, entity, delivery_time_days,supplier_reputation)";
+                $sql .= " values('" . $this->db->idate($now) . "',";
+                $sql .= " " . $this->id . ",";
+                $sql .= " " . $fourn->id . ",";
+                $sql .= " '" . $this->db->escape($ref_fourn) . "',";
+                $sql .= " " . $user->id . ",";
+                $sql .= " " . $buyprice . ",";
+                $sql .= " " . $qty . ",";
+                $sql .= " " . $remise_percent . ",";
+                $sql .= " " . $remise . ",";
+                $sql .= " " . $unitBuyPrice . ",";
+                $sql .= " " . $tva_tx . ",";
+                $sql .= " " . $charges . ",";
+                $sql .= " " . $unitCharges . ",";
+                $sql .= " " . $availability . ",";
+                $sql .= " " . $newnpr . ",";
+                $sql .= $conf->entity . ",";
+                $sql .= $delivery_time_days . ",";
+                $sql .= (empty($supplier_reputation) ? 'NULL' : "'" . $this->db->escape($supplier_reputation) . "'");
+                $sql .= ")";
+                
+                $idinserted = 0;
+                
+                $resql = $this->db->query($sql);
+                if ($resql) {
+                    $idinserted = $this->db->last_insert_id(MAIN_DB_PREFIX . "product_fournisseur_price");
+                }
+                else {
+                    $error++;
+                }
+                
+                if (! $error && ! empty($conf->global->PRODUCT_PRICE_SUPPLIER_NO_LOG)) {
+                    // Add record into log table
+                    $sql = "INSERT INTO " . MAIN_DB_PREFIX . "product_fournisseur_price_log(";
+                    $sql .= "datec, fk_product_fournisseur,fk_user,price,quantity)";
+                    $sql .= "values('" . $this->db->idate($now) . "',";
+                    $sql .= " " . $this->product_fourn_id . ",";
+                    $sql .= " " . $user->id . ",";
+                    $sql .= " " . price2num($buyprice) . ",";
+                    $sql .= " " . $qty;
+                    $sql .= ")";
+                    
+                    $resql = $this->db->query($sql);
+                    if (! $resql) {
+                        $error++;
+                    }
+                }
+                
+                if (! $error) {
+                    // Call trigger
+                    $result = $this->call_trigger('SUPPLIER_PRODUCT_BUYPRICE_CREATE', $user);
+                    if ($result < 0)
+                        $error++;
                         // End call triggers
-
-        				if (empty($error))
-        				{
-        					$this->db->commit();
-        					return 0;
-        				}
-        				else
-        				{
-        					$this->db->rollback();
-        					return -1;
-        				}
-		            }
-		            else
-		            {
-		                $this->error=$this->db->error()." sql=".$sql;
-		                $this->db->rollback();
-		                return -2;
-		            }
-		        }
-		        else
-		        {
-		            $this->error=$this->db->error()." sql=".$sql;
-		            $this->db->rollback();
-		            return -1;
-		        }
-		    }
+                    
+                    if (empty($error)) {
+                        $this->db->commit();
+                        return $idinserted;
+                    } else {
+                        $this->db->rollback();
+                        return -1;
+                    }
+                } else {
+                    $this->error = $this->db->lasterror() . " sql=" . $sql;
+                    $this->db->rollback();
+                    return -2;
+                }
+            } else {
+                $this->error = $this->db->lasterror() . " sql=" . $sql;
+                $this->db->rollback();
+                return - 1;
+            }
+        }
     }
 
     /**
diff --git a/htdocs/product/class/product.class.php b/htdocs/product/class/product.class.php
index 98684d5f980..d242a343ce9 100644
--- a/htdocs/product/class/product.class.php
+++ b/htdocs/product/class/product.class.php
@@ -1315,21 +1315,21 @@ class Product extends CommonObject
 	 *  @param     	double	$qty                Quantity asked
 	 *	@param		int		$product_id			Filter on a particular product id
 	 * 	@param		string	$fourn_ref			Filter on a supplier ref
-	 *  @return    	int 						<-1 if KO, -1 if qty not enough, 0 si ok mais rien trouve, id_product si ok et trouve. May also initialize some properties like (->ref_supplier, buyprice, fourn_pu, vatrate_supplier...)
+	 *  @return    	int 						<-1 if KO, -1 if qty not enough, 0 if OK but nothing found, id_product if OK and found. May also initialize some properties like (->ref_supplier, buyprice, fourn_pu, vatrate_supplier...)
 	 */
 	function get_buyprice($prodfournprice,$qty,$product_id=0,$fourn_ref=0)
 	{
 		global $conf;
 		$result = 0;
 
-		// We do select by searching with qty and prodfournprice
+		// We do a first seach with a select by searching with couple prodfournprice and qty only (later we will search on triplet qty/product_id/fourn_ref)
 		$sql = "SELECT pfp.rowid, pfp.price as price, pfp.quantity as quantity,";
 		$sql.= " pfp.fk_product, pfp.ref_fourn, pfp.fk_soc, pfp.tva_tx, pfp.fk_supplier_price_expression";
 		$sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
 		$sql.= " WHERE pfp.rowid = ".$prodfournprice;
 		if ($qty) $sql.= " AND pfp.quantity <= ".$qty;
 
-		dol_syslog(get_class($this)."::get_buyprice", LOG_DEBUG);
+		dol_syslog(get_class($this)."::get_buyprice first search by prodfournprice/qty", LOG_DEBUG);
 		$resql = $this->db->query($sql);
 		if ($resql)
 		{
@@ -1358,9 +1358,9 @@ class Product extends CommonObject
 				$result=$obj->fk_product;
 				return $result;
 			}
-			else
+			else // If not found
 			{
-				// We do same select again but searching with qty, ref and id product
+				// We do a second search by doing a select again but searching with qty, ref and id product
 				$sql = "SELECT pfp.rowid, pfp.price as price, pfp.quantity as quantity, pfp.fk_soc,";
 				$sql.= " pfp.fk_product, pfp.ref_fourn as ref_supplier, pfp.tva_tx, pfp.fk_supplier_price_expression";
 				$sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
@@ -1370,7 +1370,7 @@ class Product extends CommonObject
 				$sql.= " ORDER BY pfp.quantity DESC";
 				$sql.= " LIMIT 1";
 
-				dol_syslog(get_class($this)."::get_buyprice", LOG_DEBUG);
+				dol_syslog(get_class($this)."::get_buyprice second search from qty/ref/product_id", LOG_DEBUG);
 				$resql = $this->db->query($sql);
 				if ($resql)
 				{
@@ -2656,6 +2656,8 @@ class Product extends CommonObject
 
 		$now=dol_now();
 
+    	dol_syslog(get_class($this)."::add_fournisseur id_fourn = ".$id_fourn." ref_fourn=".$ref_fourn." quantity=".$quantity, LOG_DEBUG);
+    	
 		if ($ref_fourn)
 		{
     		$sql = "SELECT rowid, fk_product";
@@ -2665,7 +2667,6 @@ class Product extends CommonObject
     		$sql.= " AND fk_product != ".$this->id;
     		$sql.= " AND entity = ".$conf->entity;
 
-    		dol_syslog(get_class($this)."::add_fournisseur", LOG_DEBUG);
     		$resql=$this->db->query($sql);
     		if ($resql)
     		{
@@ -2689,7 +2690,6 @@ class Product extends CommonObject
 		$sql.= " AND fk_product = ".$this->id;
 		$sql.= " AND entity = ".$conf->entity;
 
-		dol_syslog(get_class($this)."::add_fournisseur", LOG_DEBUG);
 		$resql=$this->db->query($sql);
 		if ($resql)
 		{
@@ -2718,7 +2718,6 @@ class Product extends CommonObject
 				$sql.= ", 0";
 				$sql.= ")";
 
-				dol_syslog(get_class($this)."::add_fournisseur", LOG_DEBUG);
 				if ($this->db->query($sql))
 				{
 					$this->product_fourn_price_id = $this->db->last_insert_id(MAIN_DB_PREFIX."product_fournisseur_price");
diff --git a/test/phpunit/CommandeFournisseurTest.php b/test/phpunit/CommandeFournisseurTest.php
index 67c120a2bb8..03880a56eca 100644
--- a/test/phpunit/CommandeFournisseurTest.php
+++ b/test/phpunit/CommandeFournisseurTest.php
@@ -145,7 +145,7 @@ class CommandeFournisseurTest extends PHPUnit_Framework_TestCase
         // Create supplier price
         $result=$product->add_fournisseur($user, $societe->id, $ref_fourn, $quantity);    // This insert record with no value for price. Values are update later with update_buyprice
         $this->assertGreaterThanOrEqual(1, $result);
-        $result=$product->update_buyprice($quantity, 10, $user, 'HT', $societe, '', $ref_fourn, $tva_tx, 0, 0);
+        $result=$product->update_buyprice($quantity, 20, $user, 'HT', $societe, '', $ref_fourn, $tva_tx, 0, 0);
         $this->assertGreaterThanOrEqual(0, $result);
 
         // Create supplier order with a too low quantity