src/net/url/url.go      | 18 ++++++++++++++++--
 src/net/url/url_test.go | 24 +++++++++++++++++++++++-

diff --git a/src/net/url/url.go b/src/net/url/url.go
index efbb4c36e9bf0419619d4dfdffc26d578a8a0f9a..8ffad663d5cf062e96055131a48a5c51cab66434 100644
--- a/src/net/url/url.go
+++ b/src/net/url/url.go
@@ -550,8 +550,22 @@ // validEncodedPath reports whether s is a valid encoded path.
 // It must not contain any bytes that require escaping during path encoding.
 func validEncodedPath(s string) bool {
 	for i := 0; i < len(s); i++ {
-		if s[i] != '%' && shouldEscape(s[i], encodePath) {
-			return false
+		// RFC 3986, Appendix A.
+		// pchar = unreserved / pct-encoded / sub-delims / ":" / "@".
+		// shouldEscape is not quite compliant with the RFC,
+		// so we check the sub-delims ourselves and let
+		// shouldEscape handle the others.
+		switch s[i] {
+		case '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=', ':', '@':
+			// ok
+		case '[', ']':
+			// ok - not specified in RFC 3986 but left alone by modern browsers
+		case '%':
+			// ok - percent encoded, will decode
+		default:
+			if shouldEscape(s[i], encodePath) {
+				return false
+			}
 		}
 	}
 	return true
diff --git a/src/net/url/url_test.go b/src/net/url/url_test.go
index 80a2b80efad32e80994f54a2fa1a05db9750c930..ff6e9e4541a7b6b524f74e02808bedfc5f464406 100644
--- a/src/net/url/url_test.go
+++ b/src/net/url/url_test.go
@@ -392,13 +392,35 @@ 			Path:   "/bar",
 		},
 		"",
 	},
-	// worst case host
+	// worst case host, still round trips
 	{
 		"scheme://!$&'()*+,;=hello!:port/path",
 		&URL{
 			Scheme: "scheme",
 			Host:   "!$&'()*+,;=hello!:port",
 			Path:   "/path",
+		},
+		"",
+	},
+	// worst case path, still round trips
+	{
+		"http://host/!$&'()*+,;=:@[hello]",
+		&URL{
+			Scheme:  "http",
+			Host:    "host",
+			Path:    "/!$&'()*+,;=:@[hello]",
+			RawPath: "/!$&'()*+,;=:@[hello]",
+		},
+		"",
+	},
+	// golang.org/issue/5684
+	{
+		"http://example.com/oid/[order_id]",
+		&URL{
+			Scheme:  "http",
+			Host:    "example.com",
+			Path:    "/oid/[order_id]",
+			RawPath: "/oid/[order_id]",
 		},
 		"",
 	},