MDL-78550 grade: Hide empty filler rows from the accessibility tree

grade/edit/tree/lib.php

@@ -300,11 +300,13 @@ public function build_html_tree($element, $totals, $parents, $level, &$row_count
             $parentcategories = array_merge($rowclasses, [$eid]);
             $emptyrow->attributes['class'] = 'spacer ' . implode(' ', $parentcategories);
             $emptyrow->attributes['data-hidden'] = 'false';
+            $emptyrow->attributes['aria-hidden'] = 'true';
 
             $headercell = new html_table_cell();
             $headercell->header = true;
             $headercell->scope = 'row';
             $headercell->attributes['class'] = 'cell column-rowspan rowspan';
+            $headercell->attributes['aria-hidden'] = 'true';
             $headercell->rowspan = $row_count;
             $emptyrow->cells[] = $headercell;
 
@@ -314,6 +316,7 @@ public function build_html_tree($element, $totals, $parents, $level, &$row_count
             $endcell = new html_table_cell();
             $endcell->colspan = (19 - $level);
             $endcell->attributes['class'] = 'emptyrow colspan ' . $levelclass;
+            $endcell->attributes['aria-hidden'] = 'true';
 
             $returnrows[] = new html_table_row(array($endcell));