diff --git a/htdocs/compta/facture/class/facture.class.php b/htdocs/compta/facture/class/facture.class.php
index 67f58ac9875..afefb4fc532 100644
--- a/htdocs/compta/facture/class/facture.class.php
+++ b/htdocs/compta/facture/class/facture.class.php
@@ -1277,7 +1277,7 @@ class Facture extends CommonInvoice
 	{
 		$this->lines=array();
 
-		$sql = 'SELECT l.rowid, l.fk_product, l.fk_parent_line, l.label as custom_label, l.description, l.product_type, l.price, l.qty, l.vat_src_code, l.tva_tx,';
+		$sql = 'SELECT l.rowid, l.fk_facture, l.fk_product, l.fk_parent_line, l.label as custom_label, l.description, l.product_type, l.price, l.qty, l.vat_src_code, l.tva_tx,';
 		$sql.= ' l.situation_percent, l.fk_prev_id,';
 		$sql.= ' l.localtax1_tx, l.localtax2_tx, l.localtax1_type, l.localtax2_type, l.remise_percent, l.fk_remise_except, l.subprice,';
 		$sql.= ' l.rang, l.special_code,';
@@ -1304,6 +1304,7 @@ class Facture extends CommonInvoice
 
 				$line->id               = $objp->rowid;
 				$line->rowid	        = $objp->rowid;             // deprecated
+				$line->fk_facture       = $objp->fk_facture;
 				$line->label            = $objp->custom_label;		// deprecated
 				$line->desc             = $objp->description;		// Description line
 				$line->description      = $objp->description;		// Description line
@@ -1558,6 +1559,18 @@ class Facture extends CommonInvoice
 			$facligne->rang=-1;
 			$facligne->info_bits=2;
 
+			// Get buy/cost price of invoice that is source of discount
+			if ($remise->fk_facture_source > 0)
+			{
+    			$srcinvoice=new Facture($this->db);
+    			$srcinvoice->fetch($remise->fk_facture_source);
+    			$totalcostpriceofinvoice=0;
+    			include_once DOL_DOCUMENT_ROOT.'/core/class/html.formmargin.class.php';  // TODO Move this into commonobject
+    			$formmargin=new FormMargin($this->db);
+    			$arraytmp=$formmargin->getMarginInfosArray($srcinvoice, false);
+        		$facligne->pa_ht = $arraytmp['pa_total'];
+			}
+			
 			$facligne->total_ht  = -$remise->amount_ht;
 			$facligne->total_tva = -$remise->amount_tva;
 			$facligne->total_ttc = -$remise->amount_ttc;
diff --git a/htdocs/core/class/html.formmargin.class.php b/htdocs/core/class/html.formmargin.class.php
index 0ac6012f271..2cf82424a4e 100644
--- a/htdocs/core/class/html.formmargin.class.php
+++ b/htdocs/core/class/html.formmargin.class.php
@@ -48,6 +48,7 @@ class FormMargin
 
 	/**
 	 *	get array with margin information from lines of object
+	 *  TODO Move this in common class.
 	 *
 	 * 	@param	CommonObject	$object			Object we want to get margin information for
 	 * 	@param 	boolean			$force_price	True of not
@@ -92,19 +93,23 @@ class FormMargin
 				$line->pa_ht = $line->subprice * (1 - ($line->remise_percent / 100));
 			}
 
+			$pv = $line->qty * $line->subprice * (1 - $line->remise_percent / 100);
+			$pa_ht = ($pv < 0 ? - $line->pa_ht : $line->pa_ht);      // We choosed to have line->pa_ht always positive in database, so we guess the correct sign
+			$pa = $line->qty * $pa_ht;
+			
 			// calcul des marges
 			if (isset($line->fk_remise_except) && isset($conf->global->MARGIN_METHODE_FOR_DISCOUNT)) {    // remise
-			    $pa = $line->qty * $line->pa_ht;
-			    $pv = $line->qty * $line->subprice * (1 - $line->remise_percent / 100);
 				if ($conf->global->MARGIN_METHODE_FOR_DISCOUNT == '1') { // remise globale considérée comme produit
 					$marginInfos['pa_products'] += $pa;
 					$marginInfos['pv_products'] += $pv;
 					$marginInfos['pa_total'] +=  $pa;
 					$marginInfos['pv_total'] +=  $pv;
 					// if credit note, margin = -1 * (abs(selling_price) - buying_price)
-					if ($pv < 0)
-						$marginInfos['margin_on_products'] += -1 * (abs($pv) - $pa);
-					else
+					//if ($pv < 0)
+					//{
+					//	$marginInfos['margin_on_products'] += -1 * (abs($pv) - $pa);
+					//}
+					//else
 						$marginInfos['margin_on_products'] += $pv - $pa;
 				}
 				elseif ($conf->global->MARGIN_METHODE_FOR_DISCOUNT == '2') { // remise globale considérée comme service
@@ -113,9 +118,9 @@ class FormMargin
 					$marginInfos['pa_total'] +=  $pa;
 					$marginInfos['pv_total'] +=  $pv;
 					// if credit note, margin = -1 * (abs(selling_price) - buying_price)
-					if ($pv < 0)
-						$marginInfos['margin_on_services'] += -1 * (abs($pv) - $pa);
-					else
+					//if ($pv < 0)
+					//	$marginInfos['margin_on_services'] += -1 * (abs($pv) - $pa);
+					//else
 						$marginInfos['margin_on_services'] += $pv - $pa;
 				}
 				elseif ($conf->global->MARGIN_METHODE_FOR_DISCOUNT == '3') { // remise globale prise en compte uniqt sur total
@@ -126,29 +131,29 @@ class FormMargin
 			else {
 				$type=$line->product_type?$line->product_type:$line->fk_product_type;
 				if ($type == 0) {  // product
-				    $pa = $line->qty * $line->pa_ht;
-				    $pv = $line->qty * $line->subprice * (1 - $line->remise_percent / 100);
 					$marginInfos['pa_products'] += $pa;
 					$marginInfos['pv_products'] += $pv;
 					$marginInfos['pa_total'] +=  $pa;
 					$marginInfos['pv_total'] +=  $pv;
 					// if credit note, margin = -1 * (abs(selling_price) - buying_price)
-					if ($pv < 0)
-						$marginInfos['margin_on_products'] += -1 * (abs($pv) - $pa);
-					else
-						$marginInfos['margin_on_products'] += $pv - $pa;
+					//if ($pv < 0)
+					//{
+					//    $marginInfos['margin_on_products'] += -1 * (abs($pv) - $pa);
+					//}
+					//else
+					//{
+					    $marginInfos['margin_on_products'] += $pv - $pa;
+					//}
 				}
 				elseif ($type == 1) {  // service
-				    $pa = $line->qty * $line->pa_ht;
-				    $pv = $line->qty * $line->subprice * (1 - $line->remise_percent / 100);
 					$marginInfos['pa_services'] += $pa;
 					$marginInfos['pv_services'] += $pv;
 					$marginInfos['pa_total'] +=  $pa;
 					$marginInfos['pv_total'] +=  $pv;
 					// if credit note, margin = -1 * (abs(selling_price) - buying_price)
-					if ($pv < 0)
-						$marginInfos['margin_on_services'] += -1 * (abs($pv) - $pa);
-					else
+					//if ($pv < 0)
+					//	$marginInfos['margin_on_services'] += -1 * (abs($pv) - $pa);
+					//else
 						$marginInfos['margin_on_services'] += $pv - $pa;
 				}
 			}
@@ -164,9 +169,9 @@ class FormMargin
 			$marginInfos['mark_rate_services'] = 100 * $marginInfos['margin_on_services'] / $marginInfos['pv_services'];
 
 		// if credit note, margin = -1 * (abs(selling_price) - buying_price)
-		if ($marginInfos['pv_total'] < 0)
-			$marginInfos['total_margin'] = -1 * (abs($marginInfos['pv_total']) - $marginInfos['pa_total']);
-		else
+		//if ($marginInfos['pv_total'] < 0)
+		//	$marginInfos['total_margin'] = -1 * (abs($marginInfos['pv_total']) - $marginInfos['pa_total']);
+		//else
 			$marginInfos['total_margin'] = $marginInfos['pv_total'] - $marginInfos['pa_total'];
 		if ($marginInfos['pa_total'] > 0)
 			$marginInfos['total_margin_rate'] = 100 * $marginInfos['total_margin'] / $marginInfos['pa_total'];
diff --git a/htdocs/core/tpl/objectline_view.tpl.php b/htdocs/core/tpl/objectline_view.tpl.php
index 62d4b0007ed..1c600655bdc 100755
--- a/htdocs/core/tpl/objectline_view.tpl.php
+++ b/htdocs/core/tpl/objectline_view.tpl.php
@@ -70,19 +70,20 @@ if (empty($usemargins)) $usemargins=0;
 		<?php
 		if ($line->description)
 		{
-			if ($line->description == '(CREDIT_NOTE)' && $objp->fk_remise_except > 0)
+			if ($line->description == '(CREDIT_NOTE)' && $line->fk_remise_except > 0)
 			{
 				$discount=new DiscountAbsolute($this->db);
 				$discount->fetch($line->fk_remise_except);
 				echo ($txt?' - ':'').$langs->transnoentities("DiscountFromCreditNote",$discount->getNomUrl(0));
 			}
-			elseif ($line->description == '(DEPOSIT)' && $objp->fk_remise_except > 0)
+			elseif ($line->description == '(DEPOSIT)' && $line->fk_remise_except > 0)
 			{
 				$discount=new DiscountAbsolute($this->db);
 				$discount->fetch($line->fk_remise_except);
 				echo ($txt?' - ':'').$langs->transnoentities("DiscountFromDeposit",$discount->getNomUrl(0));
 				// Add date of deposit
-				if (! empty($conf->global->INVOICE_ADD_DEPOSIT_DATE)) echo ' ('.dol_print_date($discount->datec).')';
+				if (! empty($conf->global->INVOICE_ADD_DEPOSIT_DATE)) 
+				    echo ' ('.dol_print_date($discount->datec).')';
 			}
 			else
 			{
diff --git a/htdocs/margin/agentMargins.php b/htdocs/margin/agentMargins.php
index 26a5813c8be..c7a0af0b605 100644
--- a/htdocs/margin/agentMargins.php
+++ b/htdocs/margin/agentMargins.php
@@ -120,6 +120,7 @@ $sql = "SELECT";
 if ($agentid > 0) $sql.= " s.rowid as socid, s.nom as name, s.code_client, s.client,";
 $sql.= " u.rowid as agent, u.login, u.lastname, u.firstname,";
 $sql.= " sum(d.total_ht) as selling_price,";
+// Note: qty and buy_price_ht is always positive (if not your database may be corrupted, you can update this)
 $sql.= " sum(".$db->ifsql('d.total_ht < 0','d.qty * d.buy_price_ht * -1','d.qty * d.buy_price_ht').") as buying_price,";
 $sql.= " sum(".$db->ifsql('d.total_ht < 0','-1 * (abs(d.total_ht) - (d.buy_price_ht * d.qty))','d.total_ht - (d.buy_price_ht * d.qty)').") as marge" ;
 $sql.= " FROM ".MAIN_DB_PREFIX."societe as s";
diff --git a/htdocs/margin/customerMargins.php b/htdocs/margin/customerMargins.php
index 8bdff263ebf..abfb89171dd 100644
--- a/htdocs/margin/customerMargins.php
+++ b/htdocs/margin/customerMargins.php
@@ -173,6 +173,7 @@ $sql = "SELECT";
 $sql.= " s.rowid as socid, s.nom as name, s.code_client, s.client,";
 if ($client) $sql.= " f.rowid as facid, f.facnumber, f.total as total_ht, f.datef, f.paye, f.fk_statut as statut,";
 $sql.= " sum(d.total_ht) as selling_price,";
+// Note: qty and buy_price_ht is always positive (if not your database may be corrupted, you can update this)
 $sql.= " sum(".$db->ifsql('d.total_ht < 0','d.qty * d.buy_price_ht * -1','d.qty * d.buy_price_ht').") as buying_price,";
 $sql.= " sum(".$db->ifsql('d.total_ht < 0','-1 * (abs(d.total_ht) - (d.buy_price_ht * d.qty))','d.total_ht - (d.buy_price_ht * d.qty)').") as marge";
 $sql.= " FROM ".MAIN_DB_PREFIX."societe as s";
diff --git a/htdocs/margin/lib/margins.lib.php b/htdocs/margin/lib/margins.lib.php
index 84d7945ec0d..d7dbd5d81eb 100644
--- a/htdocs/margin/lib/margins.lib.php
+++ b/htdocs/margin/lib/margins.lib.php
@@ -109,7 +109,7 @@ function marges_prepare_head()
  * @param 	float	$localtax2_tx		Vat rate special 2 (not used)
  * @param 	int		$fk_pa				Id of buying price (prefer set this to 0 and provide $paht instead. With id, buying price may have change)
  * @param 	float	$paht				Buying price without tax
- * @return	array						Array of margin info
+ * @return	array						Array of margin info (buying price, marge rate, marque rate)
  */
 function getMarginInfos($pvht, $remise_percent, $tva_tx, $localtax1_tx, $localtax2_tx, $fk_pa, $paht)
 {
@@ -134,7 +134,7 @@ function getMarginInfos($pvht, $remise_percent, $tva_tx, $localtax1_tx, $localta
 	}
 	else
 	{
-		$paht_ret	= $paht;
+		$paht_ret = $paht;
 	}
 
 	// Calculate selling unit price including line discount
diff --git a/htdocs/margin/productMargins.php b/htdocs/margin/productMargins.php
index 26d5accf710..ff06d6ce69e 100644
--- a/htdocs/margin/productMargins.php
+++ b/htdocs/margin/productMargins.php
@@ -169,6 +169,7 @@ $sql = "SELECT p.label, p.rowid, p.fk_product_type, p.ref, p.entity as pentity,"
 if ($id > 0) $sql.= " d.fk_product,";
 if ($id > 0) $sql.= " f.rowid as facid, f.facnumber, f.total as total_ht, f.datef, f.paye, f.fk_statut as statut,";
 $sql.= " SUM(d.total_ht) as selling_price,";
+// Note: qty and buy_price_ht is always positive (if not your database may be corrupted, you can update this)
 $sql.= " SUM(".$db->ifsql('d.total_ht < 0','d.qty * d.buy_price_ht * -1','d.qty * d.buy_price_ht').") as buying_price,";
 $sql.= " SUM(".$db->ifsql('d.total_ht < 0','-1 * (abs(d.total_ht) - (d.buy_price_ht * d.qty))','d.total_ht - (d.buy_price_ht * d.qty)').") as marge";
 $sql.= " FROM ".MAIN_DB_PREFIX."societe as s";
diff --git a/htdocs/societe/soc.php b/htdocs/societe/soc.php
index 540c3aed883..374a87c72ef 100644
--- a/htdocs/societe/soc.php
+++ b/htdocs/societe/soc.php
@@ -514,7 +514,7 @@ if (empty($reshook))
                 }
                 else
 				{
-				    if ($db->lasterrno() == 'DB_ERROR_RECORD_ALREADY_EXISTS') // TODO Sometime errors on duplicate on profid and not on code, so
+				    if ($db->lasterrno() == 'DB_ERROR_RECORD_ALREADY_EXISTS') // TODO Sometime errors on duplicate on profid and not on code, so we must manage this case
 					{
 						$duplicate_code_error = true;
 						$object->code_fournisseur = null;