Fix/support/da028241/situation ratio denominator

ChangeLog_loukta

@@ -1,4 +1,5 @@
 ***** ChangeLog for loukta *****
+- FIX DA028241 - FactureLigne::getSituationRatio() - wrong denominator (100 instead of situation_percent) in mode 1 caused incorrect line amounts in situation invoice PDFs. - *18/06/2026*
 - FIX DA027405 - merging PR Dolibarr#36503 in advance for Loukta: PDF for situation invoices uses legacy calculations
  (cumulative) instead of the new algorithm (delta). Once the community PR is merged, this specific code can be discarded
  and replaced with the community equivalent. - *03/12/2025*

htdocs/compta/facture/class/factureligne.class.php

@@ -996,12 +996,15 @@ public function getAllPrevProgress($invoiceid, $include_credit_note = true)
 	public function getSituationRatio()
 	{
 		if (getDolGlobalInt('INVOICE_USE_SITUATION') === 1) {
-			// in legacy mode, the situation invoice line stores the (cumulative) state of the
-			// cycle at the current situation. To get the delta, we need to subtract the
-			// state at the previous situation (if applicable).
+			// Legacy mode: line stores the cumulative state (e.g. 70%). To get the delta ratio
+			// we divide by situation_percent, not by 100 — because total_ht is already scaled
+			// by situation_percent/100, so the multiplier must cancel that factor out.
+			if (empty($this->situation_percent)) {
+				return 0;
+			}
 			$prevProgress = $this->get_prev_progress($this->fk_facture);
 
-			return ($this->situation_percent - $prevProgress) / 100;
+			return ($this->situation_percent - $prevProgress) / $this->situation_percent;
 		}
 		// new mode (INVOICE_USE_SITUATION == 2):
 		// no ratio needed (data stored on line is already a delta)