🐛 导入空内容 Markdown 文件时报错 Fix https://github.com/siyuan-note/siyuan/issues/6832

kernel/model/box.go

@@ -464,6 +464,10 @@ func parseKTree(kramdown []byte) (ret *parse.Tree) {
 }
 
 func genTreeID(tree *parse.Tree) {
+	if nil == tree.Root.FirstChild {
+		tree.Root.AppendChild(parse.NewParagraph())
+	}
+
 	ast.Walk(tree.Root, func(n *ast.Node, entering bool) ast.WalkStatus {
 		if !entering {
 			return ast.WalkContinue