Currently, parsePostForm is private. It is called only from ParseForm and one cannot call manually. This means that if one wants to call it on a non-standard HTTP method (not POST, PUT, PATCH) you have to temporary change method, then call ParseForm and then return it back. Or if you want to parse just post form and ignore any query string parameters. Currently you cannot ignore string parameters (you have to set RawQueryString to "" currently). In my case, I want to parse query string and post form separately because I want o log parsed query string but not post form (the latter might have sensitive data).

I think code could be something like:

func (r *Request) ParsePostForm() error {
	var err error
	if r.PostForm == nil {
		r.PostForm, err = parsePostForm(r)
		if r.PostForm == nil {
			r.PostForm = make(url.Values)
		}
	}
	return err
}

func (r *Request) ParseForm() error {
	var err error
	if r.PostForm == nil {
		if r.Method == "POST" || r.Method == "PUT" || r.Method == "PATCH" {
			err = r.ParsePostForm()
		}
		if r.PostForm == nil {
			r.PostForm = make(url.Values)
		}
	}
	...
}