After I posted last article, I found it’s not validated and the HTML Validator showed me where the error is. I traced the source code of WordPress, made a little modification, and then solved the problem. That’s not the point. The point is, I decided to report the bug to the development team. I went on the official web site, simply searched the forum and the tickets system to make sure that no one had reported this, registered an account (although it’s not necessary… XD), filled the ticket form, and then submitted it.
I don’t know if this patch will be received or not, and the problem is not critical, but for me, it’s worthy to write it down. I’ve used WordPress for such a long time, and this is the first time I do something for it. ^^a