net/url: parseQuery() better support for array parse.

[ainilili]

What version of Go are you using (go version)?

$ 1.15.3

Does this issue reproduce with the latest release?

yes

What did you do?

import (
	"fmt"
	"net/url"
)

func main(){
	query := "params=fo,fu,n%2Cico"
	values, err := url.ParseQuery(query)
	if err != nil{
		panic(err)
	}
	for _, vs := range values{
		for _, v := range vs{
			fmt.Println(v)
		}
	}
}

What did you expect to see?

fo
fu
n,ico

What did you see instead?

fo,fu,n,ico

When an Array parameter is passed by URL or application/ x-www-Form-urlencoded mode, many clients will define the request content in a comma-separated way, so can this expectation be met?

[seankhliao]

That does not appear to be standard behaviour https://url.spec.whatwg.org/#urlencoded-parsing

And in this case, how would valid values containing commas be preserved?

[imxyb]

I also think this is more of a business scenario, not suitable for general use

[ainilili]

That does not appear to be standard behaviour https://url.spec.whatwg.org/#urlencoded-parsing

And in this case, how would valid values containing commas be preserved?

If a valid value needs to contain a comma, just escape it to %2C before initiating the request. But then again, it's not standard.

[ainilili]

I also think this is more of a business scenario, not suitable for general use

That does not appear to be standard behaviour https://url.spec.whatwg.org/#urlencoded-parsing
And in this case, how would valid values containing commas be preserved?

If a valid value needs to contain a comma, just escape it to %2C before initiating the request. But then again, it's not standard.

However, while this practice is not standard, if it becomes standard, it may be possible to request data transfers:

tags=a&tags=b&tags=c

simplified to:

tags=a,b,c

Of course, this is just a personal thought. xD

[ainilili]

I also think this is more of a business scenario, not suitable for general use

Well, in order not to break the standards, I should implement this functionality in the application framework layer.