Gin master build failed

[chainhelen]

@thinkerou @appleboy
Gin master, the commit is 0da5b0c85ac2539e775a7e63aebf3e0b5808dab4

Description

refercens
#1510 test(not review): add go1.11
#1383 Support map as query string or post form parameters
#1362 How can I get map[string]string filed on PostForm?
#1106 Map as query parameter

Build failed in go master but ok in other go version.

Reason

This because this commit in go master, add this func validQuery

// validQuery reports whether s is a valid query string per RFC 3986
// Section 3.4:
//     query       = *( pchar / "/" / "?" )
//     pchar       = unreserved / pct-encoded / sub-delims / ":" / "@"
//     unreserved  = ALPHA / DIGIT / "-" / "." / "_" / "~"
//     sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
//                   / "*" / "+" / "," / ";" / "="
func validQuery(s string) bool {
   pctEnc := 0
	for _, r := range s {
   	if pctEnc > 0 {
   		if uint32(r) > 255 || !ishex(byte(r)) {
   			return false
   		}
   		pctEnc--
   		continue
   	} else if r == '%' {
   		pctEnc = 2
   		continue
   	}
		if 'A' <= r && r <= 'Z' {
   		continue
   	}
   	if 'a' <= r && r <= 'z' {
   		continue
   	}
   	if '0' <= r && r <= '9' {
   		continue
   	}
   	switch r {
   	case '-', '.', '_', '~', '!', '$', '&', '\'', '(', ')',
   		'*', '+', ',', ';', '=', ':', '@', '/', '?':
   		continue
   	default:
   		return false
   	}
   }
	return true
}

Then I copy these into local workspace, test like below

func main() {
    fmt.Printf("%t\n", validQuery("both=GET&id=main&id=omit&array[]=first&array[]=second&ids[a]=hi&ids[b]=3.14"))
    fmt.Printf("%t\n", validQuery("foo=bar&page=10&id=2"))
}

// build and run, get 
false
true

Summarize

In go master, if url include '[' or ']', will be QueryEscape according to RFC 3986. So don't parse url.query

[chainhelen]

Maybe we can parse this type query in gin itself.

[thinkerou]

@chainhelen fix issue, please see #1510 and help review, thanks!