diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 6e7fff8de91..69fb00a74be 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -5702,9 +5702,10 @@ abstract class CommonObject
 
 			// Recalculate unit price with tax if not defined
 			if (empty((float) $line->subprice_ttc) && $line->qty) {	// subprice_ttc may be not stored on old version or not defined for lines with no unit price (like a discount)
-				// So we calculate an estimated value just to show something on screen
+				// So we calculate an estimated value just to show something on screen.
+				// Not: the unit price is always for 100% of line, it is not a prorata of situation invoice (when total is)
 				if ($line->remise_percent != 100) {
-					$line->subprice_ttc = (float) price2num($line->total_ttc / $line->qty / (1 - $line->remise_percent / 100), 'MU');
+					$line->subprice_ttc = (float) price2num($line->total_ttc * ($line->situation_percent ? 100 / $line->situation_percent : 1) / $line->qty / (1 - $line->remise_percent / 100), 'MU');
 				} else {
 					// Other method is less accurate
 					$line->subprice_ttc = (float) price2num((!empty($line->subprice) ? $line->subprice : 0) * (1 + ((!empty($line->tva_tx) ? $line->tva_tx : 0) / 100)), 'MU');
@@ -6810,7 +6811,7 @@ abstract class CommonObject
 				if (empty($extrafields->attributes[$this->table_element]['type'][$name]) || (!in_array($extrafields->attributes[$this->table_element]['type'][$name], ['separate', 'point', 'multipts', 'linestrg','polygon']))) {
 					$sql .= ", ".$this->db->sanitize($name);
 				}
-				// use geo sql fonction to read as text
+				// use geo sql function to read as text
 				if (!empty($extrafields->attributes[$this->table_element]['type'][$name]) && in_array($extrafields->attributes[$this->table_element]['type'][$name], array('point', 'multipts', 'linestrg', 'polygon'))) {
 					// TODO Add an abstraction method in the database driver
 					$sql .= ", ST_AsWKT(".$name.") as ".$this->db->sanitize($name);
diff --git a/htdocs/core/tpl/objectline_edit.tpl.php b/htdocs/core/tpl/objectline_edit.tpl.php
index a905cdc008f..4e0cbd52d17 100644
--- a/htdocs/core/tpl/objectline_edit.tpl.php
+++ b/htdocs/core/tpl/objectline_edit.tpl.php
@@ -43,6 +43,7 @@
  * @var Translate $langs
  * @var User $user
  * @var ExtraFields $extrafields
+ *
  * @var CommonObject $this
  * @var CommonObject $object
  * @var CommonObjectLine $line
@@ -69,6 +70,8 @@ if (empty($object) || !is_object($object)) {
 @phan-var-force int $i
 ';
 
+global $db;
+
 // Handle subtotals line edit
 if (defined('SUBTOTALS_SPECIAL_CODE') && $line->special_code == SUBTOTALS_SPECIAL_CODE) {
 	return require DOL_DOCUMENT_ROOT.'/core/tpl/subtotal_edit.tpl.php';
@@ -96,6 +99,33 @@ if (empty($canchangeproduct)) {
 	$canchangeproduct = 0;
 }
 
+$situationinvoicelinewithparent = 0;
+$situationinvoicelinewithchild = 0;
+
+if (getDolGlobalInt('INVOICE_USE_SITUATION') && in_array($object->element, array('facture', 'facturedet'))) {
+	/** @var CommonInvoice $object */
+	// @phan-suppress-next-line PhanUndeclaredConstantOfClass
+
+	// Set if invoice line has a parent
+	if (isset($line->fk_prev_id)) {
+		if ($object->isSituationInvoice()) {	// Method isSituationInvoice() exists only on invoices
+			// Set constant to disallow editing during a situation cycle
+			$situationinvoicelinewithparent = 1;
+		}
+	}
+	// Set if invoice line has a child
+	$sqlcheckchild = "SELECT COUNT(rowid) FROM ".MAIN_DB_PREFIX."facturedet WHERE fk_prev_id = ".((int) $line->id);
+	$resqlcheckchild = $db->query($sqlcheckchild);
+	if ($resqlcheckchild) {
+		$objcheckchild = $db->fetch_object($resqlcheckchild);
+		if ($objcheckchild->count > 0) {
+			$situationinvoicelinewithchild = 1;
+		}
+	} else {
+		dol_print_error($db);
+	}
+}
+
 // Define colspan for the button 'Add'
 $colspan = 3; // Col total ht + col edit + col delete
 if (!empty($inputalsopricewithtax)) {
@@ -168,23 +198,7 @@ $coldisplay++;
 		$reshook = $hookmanager->executeHooks('formEditProductOptions', $parameters, $this, $action);
 	}
 
-	$situationinvoicelinewithparent = 0;
-	if ($line->fk_prev_id != null && in_array($object->element, array('facture', 'facturedet'))) {
-		/** @var CommonInvoice $object */
-		// @phan-suppress-next-line PhanUndeclaredConstantOfClass
-		if ($object->type == $object::TYPE_SITUATION) {	// The constant TYPE_SITUATION exists only for object invoice
-			// Set constant to disallow editing during a situation cycle
-			$situationinvoicelinewithparent = 1;
-		}
-	}
-
-	// Do not allow editing during a situation cycle
-	// but in some situations that is required (update legal information for example)
-	if (getDolGlobalString('INVOICE_SITUATION_CAN_FORCE_UPDATE_DESCRIPTION')) {
-		$situationinvoicelinewithparent = 0;
-	}
-
-	if (!$situationinvoicelinewithparent) {
+	if (!$situationinvoicelinewithparent || getDolGlobalString('INVOICE_SITUATION_CAN_FORCE_UPDATE_DESCRIPTION')) {
 		// editor wysiwyg
 		require_once DOL_DOCUMENT_ROOT.'/core/class/doleditor.class.php';
 		$nbrows = ROWS_2;
@@ -200,7 +214,7 @@ $coldisplay++;
 		$doleditor->Create();
 	} else {
 		print '<textarea id="product_desc" class="flat" name="product_desc" readonly style="width: 200px; height:80px;">';
-		print GETPOSTISSET('product_desc') ? GETPOST('product_desc', 'restricthtml') : $line->description;
+		print dolPrintHTMLForTextArea(GETPOSTISSET('product_desc') ? GETPOST('product_desc', 'restricthtml') : $line->description);
 		print '</textarea>';
 	}
 
diff --git a/htdocs/core/tpl/objectline_view.tpl.php b/htdocs/core/tpl/objectline_view.tpl.php
index 5ee06828e07..625888f4662 100644
--- a/htdocs/core/tpl/objectline_view.tpl.php
+++ b/htdocs/core/tpl/objectline_view.tpl.php
@@ -59,6 +59,9 @@
  * @var string $description
  * @var Object $objp
  * @var int	$dateSelector
+ * @var int	$inputalsopricewithtax
+ * @var int	$outputalsopricetotalwithtax
+ * @var int $disableremove
  */
 // Protection to avoid direct call of template
 if (empty($object) || !is_object($object)) {
@@ -108,6 +111,34 @@ if (empty($outputalsopricetotalwithtax)) {
 	$outputalsopricetotalwithtax = 0;
 }
 
+$situationinvoicelinewithparent = 0;
+$situationinvoicelinewithchild = 0;
+
+if (getDolGlobalInt('INVOICE_USE_SITUATION') && in_array($object->element, array('facture', 'facturedet'))) {
+	/** @var CommonInvoice $object */
+	// @phan-suppress-next-line PhanUndeclaredConstantOfClass
+
+	// Set if invoice line has a parent
+	if (isset($line->fk_prev_id)) {
+		if ($object->isSituationInvoice()) {	// Method isSituationInvoice() exists only on invoices
+			// Set constant to disallow editing during a situation cycle
+			$situationinvoicelinewithparent = 1;
+		}
+	}
+	// Set if invoice line has a child
+	$sqlcheckchild = "SELECT COUNT(rowid) FROM ".MAIN_DB_PREFIX."facturedet WHERE fk_prev_id = ".((int) $line->id);
+	$resqlcheckchild = $db->query($sqlcheckchild);
+	if ($resqlcheckchild) {
+		$objcheckchild = $db->fetch_object($resqlcheckchild);
+		if ($objcheckchild->count > 0) {
+			$situationinvoicelinewithchild = 1;
+		}
+	} else {
+		dol_print_error($db);
+	}
+}
+
+
 // add html5 elements
 $domData  = ' data-element="'.$line->element.'"';
 $domData .= ' data-id="'.$line->id.'"';
@@ -408,7 +439,8 @@ if (empty($positiverates)) {
 print $tooltiponprice;
 print vatrate($positiverates.($line->vat_src_code ? ' ('.$line->vat_src_code.')' : ''), true, $line->info_bits);
 print $tooltiponpriceend;
-?></td>
+print '</td>';
+?>
 
 <td class="linecoluht nowraponall right">
 	<?php
@@ -421,7 +453,9 @@ print $tooltiponpriceend;
 	?>
 </td>
 
-<?php if (isModEnabled("multicurrency") && $this->multicurrency_code && $this->multicurrency_code != $conf->currency) { ?>
+<?php
+// Multicurrency unit price excluding tax - HT
+if (isModEnabled("multicurrency") && $this->multicurrency_code && $this->multicurrency_code != $conf->currency) { ?>
 	<td class="linecoluht_currency nowraponall right">
 	<?php $coldisplay++;
 	if (empty($line->fk_remise_except)) {
@@ -433,12 +467,12 @@ print $tooltiponpriceend;
 	</td>
 <?php }
 
-// Multicurrency HT
 if (!empty($inputalsopricewithtax) && !getDolGlobalInt('MAIN_NO_INPUT_PRICE_WITH_TAX')) { ?>
 	<td class="linecoluttc nowraponall right"><?php $coldisplay++; ?><?php
 	$upinctax = isset($line->subprice_ttc) ? $line->subprice_ttc : null;
-	if (!$upinctax && $line->total_ttc && $line->qty) {
-		$upinctax = price2num($line->total_ttc / (float) $line->qty, 'MU');
+	if (!$upinctax && $line->total_ttc && $line->qty) {		// The unit price including tax was not saved, so we try to guess it
+		// Note that unit price is always for 100% of line, it is not prorata of situation percent, when total_ttc is.
+		$upinctax = price2num($line->total_ttc * ($line->situation_percent ? 100 / $line->situation_percent : 1) / (float) $line->qty, 'MU');
 	}
 	if (!$upinctax) {
 		$multicurrency_upinctax = price2num($line->multicurrency_subprice * (1 + ($line->tva_tx / 100)), 'MU'); // one tax
@@ -446,10 +480,11 @@ if (!empty($inputalsopricewithtax) && !getDolGlobalInt('MAIN_NO_INPUT_PRICE_WITH
 	if (empty($line->fk_remise_except)) {
 		print(isset($upinctax) ? price($sign * $upinctax) : price($sign * $line->subprice));
 	}	// if upinctax can't be known, we show subprice excl ta
-	?></td>
+	?>
+	</td>
 <?php }
 
-// Multicurrency TTC
+// Multicurrency unit price including tax - TTC
 if (isModEnabled("multicurrency") && $this->multicurrency_code && $this->multicurrency_code != $conf->currency && !empty($inputalsopricewithtax) && !getDolGlobalInt('MAIN_NO_INPUT_PRICE_WITH_TAX')) { ?>
 	<td class="linecoluttc_currency nowraponall right"><?php $coldisplay++; ?><?php
 	$multicurrency_upinctax = isset($line->multicurrency_subprice_ttc) ? $line->multicurrency_subprice_ttc : null;
@@ -600,16 +635,6 @@ $objectRights = $this->getRights();
 $tmppermtoedit = $objectRights->creer;
 
 if ($this->status == 0 && $tmppermtoedit && $action != 'selectlines') {
-	$situationinvoicelinewithparent = 0;
-	if (isset($line->fk_prev_id) && in_array($object->element, array('facture', 'facturedet'))) {
-		/** @var CommonInvoice $object */
-		// @phan-suppress-next-line PhanUndeclaredConstantOfClass
-		if ($object->type == $object::TYPE_SITUATION) {	// The constant TYPE_SITUATION exists only for object invoice
-			// Set constant to disallow editing during a situation cycle
-			$situationinvoicelinewithparent = 1;
-		}
-	}
-
 	// Asset info
 	if (isModEnabled('asset') && $object->element == 'invoice_supplier') {
 		print '<td class="linecolasset center">';
@@ -664,7 +689,7 @@ if ($this->status == 0 && $tmppermtoedit && $action != 'selectlines') {
 	// Delete picto
 	print '<td class="linecoldelete center">';
 	$coldisplay++;
-	if (!$situationinvoicelinewithparent && empty($disableremove)) { // For situation invoice, deletion is not possible if there is a parent company.
+	if (!$situationinvoicelinewithchild && empty($disableremove)) { // For situation invoice, deletion is not possible if there is a child line.
 		print '<a class="reposition" href="'.$_SERVER["PHP_SELF"].'?id='.$this->id.'&action=ask_deleteline&token='.newToken().'&lineid='.$line->id.'">';
 		print img_delete();
 		print '</a>';
diff --git a/htdocs/theme/eldy/btn.inc.php b/htdocs/theme/eldy/btn.inc.php
index c595980a279..7ddf5d267e6 100644
--- a/htdocs/theme/eldy/btn.inc.php
+++ b/htdocs/theme/eldy/btn.inc.php
@@ -204,7 +204,7 @@ span.butActionNewRefused>span.fa, span.butActionNewRefused>span.fa:hover
 	/* border: 1px solid #633; */
 	color: #633 !important;
 }
-.button.button-cancel, .button.button-cancel:link, .button.button-cancel:visited, .button.button-cancel:hover, .button.button-cancel:active, .button.button-cancel {
+.button.button-cancel:not(.buttongen), .button.button-cancel:link:not(.buttongen), .button.button-cancel:visited:not(.buttongen), .button.button-cancel:hover:not(.buttongen), .button.button-cancel:active:not(.buttongen), .button.button-cancel:not(.buttongen) {
 	background: var(--butactioncancelbg) !important;
 	border: none;
 	color: #333 !important;
@@ -213,7 +213,7 @@ span.butActionNewRefused>span.fa, span.butActionNewRefused>span.fa:hover
 .butActionDelete:hover {
 	box-shadow: 0px 0px 4px 1px rgba(50, 50, 50, 0.4), 0px 0px 0px rgba(60,60,60,0.1);
 }
-.button.button-cancel:hover {
+.button.button-cancel:hover:not(.buttongen) {
 	box-shadow: 0px 0px 4px 1px rgba(50, 50, 50, 0.2), 0px 0px 0px rgba(60,60,60,0.1);
 }
 
diff --git a/htdocs/theme/md/btn.inc.php b/htdocs/theme/md/btn.inc.php
index acf0cbe7976..91a9408cb3c 100644
--- a/htdocs/theme/md/btn.inc.php
+++ b/htdocs/theme/md/btn.inc.php
@@ -259,7 +259,7 @@ span.butActionNewRefused>span.fa, span.butActionNewRefused>span.fa:hover
 	background: var(--butactiondeletebg);
 	color: #633 !important;
 }
-.button.button-cancel, .button.button-cancel:link, .button.button-cancel:visited, .button.button-cancel:hover, .button.button-cancel:active, .button.button-cancel {
+.button.button-cancel:not(.buttongen), .button.button-cancel:link:not(.buttongen), .button.button-cancel:visited:not(.buttongen), .button.button-cancel:hover:not(.buttongen), .button.button-cancel:active:not(.buttongen), .button.button-cancel:not(.buttongen) {
 	background: var(--butactioncancelbg) !important;
 	color: #888 !important;
 }
@@ -267,7 +267,7 @@ span.butActionNewRefused>span.fa, span.butActionNewRefused>span.fa:hover
 .butActionDelete:hover {
 	box-shadow: 0px 0px 6px 1px rgba(50, 50, 50, 0.4), 0px 0px 0px rgba(60,60,60,0.1);
 }
-.button.button-cancel:hover {
+.button.button-cancel:hover:not(.buttongen) {
 	box-shadow: 0px 0px 4px 1px rgba(50, 50, 50, 0.2), 0px 0px 0px rgba(60,60,60,0.1);
 }