From e5808e3335591c32ec87628a3f9b6b65b30698fe Mon Sep 17 00:00:00 2001
From: Laurent Destailleur <eldy@destailleur.fr>
Date: Mon, 3 Feb 2020 04:48:17 +0100
Subject: [PATCH] FIX #12995

---
 htdocs/bom/bom_card.php                  | 8 ++++++++
 htdocs/core/class/commonobject.class.php | 7 +++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/htdocs/bom/bom_card.php b/htdocs/bom/bom_card.php
index 87396dccb30..3f1be6c7e4c 100644
--- a/htdocs/bom/bom_card.php
+++ b/htdocs/bom/bom_card.php
@@ -155,6 +155,8 @@ if (empty($reshook))
 
 		if (!$error)
 		{
+			$lastposition = 0;
+
     		$bomline = new BOMLine($db);
     		$bomline->fk_bom = $id;
     		$bomline->fk_product = $idprod;
@@ -163,6 +165,12 @@ if (empty($reshook))
     		$bomline->disable_stock_change = (int) $disable_stock_change;
     		$bomline->efficiency = $efficiency;
 
+    		// Rang to use
+   			$rangmax = $object->line_max(0);
+   			$ranktouse = $rangmax + 1;
+
+   			$bomline->position = ($ranktouse + 1);
+
     		$result = $bomline->create($user);
     		if ($result <= 0)
     		{
diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 14433ff79db..dd2973cb1fb 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -2744,10 +2744,13 @@ abstract class CommonObject
 	public function line_max($fk_parent_line = 0)
 	{
         // phpcs:enable
+        $positionfield = 'rang';
+		if ($this->table_element = 'bom') $positionfield = 'position';
+
 		// Search the last rang with fk_parent_line
 		if ($fk_parent_line)
 		{
-			$sql = 'SELECT max(rang) FROM '.MAIN_DB_PREFIX.$this->table_element_line;
+			$sql = 'SELECT max('.$positionfield.') FROM '.MAIN_DB_PREFIX.$this->table_element_line;
 			$sql .= ' WHERE '.$this->fk_element.' = '.$this->id;
 			$sql .= ' AND fk_parent_line = '.$fk_parent_line;
 
@@ -2769,7 +2772,7 @@ abstract class CommonObject
 		// If not, search the last rang of element
 		else
 		{
-			$sql = 'SELECT max(rang) FROM '.MAIN_DB_PREFIX.$this->table_element_line;
+			$sql = 'SELECT max('.$positionfield.') FROM '.MAIN_DB_PREFIX.$this->table_element_line;
 			$sql .= ' WHERE '.$this->fk_element.' = '.$this->id;
 
 			dol_syslog(get_class($this)."::line_max", LOG_DEBUG);