safari decode url when open a new page from a link

I put a httplink on page, and decode the url, but when click the link, the url automatic decode it, I researched this issue on google, someone said have fixed this issue,

but I tested use latest version safari on mac, the issue still exist.

the issue is like that: link is http://localhost/manage.aspx?return_page=%2ftestpage%2fcabinet.aspx%3f%26here

but when open the page, it will change to :

http://localhost/manage.aspx?return_page=/testpage/cabinet.aspx&here

Could someone tell me does apple fixed this issue? where is the official explaination about it?

and if not, how to avoid it in safari? thank u very much!!!