Merge pull request #49085 from pycbouh/tree-fix-long-distance-relationships

Fix disappearing relationship lines in `Tree` when item is out of view

scene/gui/tree.cpp

@@ -1865,18 +1865,24 @@ int Tree::draw_item(const Point2i &p_pos, const Point2 &p_draw_ofs, const Size2
 						prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
 					} else if (p_item->is_selected(0)) {
 						// If parent item is selected (but this item is not), we draw the line using children highlight style.
-						// Siblings of the selected branch can be drawn with a slight offset (and also don't need a vertical line).
+						// Siblings of the selected branch can be drawn with a slight offset and their vertical line must appear as highlighted.
 						if (_is_sibling_branch_selected(c)) {
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(parent_line_width / 2), root_pos.y), cache.children_hl_line_color, children_line_width);
+							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
+
+							prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
 						} else {
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(children_line_width / 2), root_pos.y), cache.children_hl_line_color, children_line_width);
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(children_line_width / 2)), Point2i(parent_pos.x, prev_ofs + Math::floor(children_line_width / 2)), cache.children_hl_line_color, children_line_width);
 						}
 					} else {
 						// If nothing of the above is true, we draw the line using normal style.
-						// Siblings of the selected branch can be drawn with a slight offset (and also don't need a vertical line).
+						// Siblings of the selected branch can be drawn with a slight offset and their vertical line must appear as highlighted.
 						if (_is_sibling_branch_selected(c)) {
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + cache.parent_hl_line_margin, root_pos.y), cache.relationship_line_color, line_width);
+							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
+
+							prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
 						} else {
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(line_width / 2), root_pos.y), cache.relationship_line_color, line_width);
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(line_width / 2)), Point2i(parent_pos.x, prev_ofs + Math::floor(line_width / 2)), cache.relationship_line_color, line_width);