fix: ipv6 address parsing

Author: mpetrunic

src/net/ip.go

@@ -618,7 +618,7 @@ func parseIPv6(s string) (ip IP) {
 	for i < IPv6len {
 		// Hex number.
 		n, c, ok := xtoi(s)
-		if !ok || n > 0xFFFF {
+		if !ok || n > 0xFFFF || c > 4 {
 			return nil
 		}
 

src/net/ip_test.go

@@ -23,7 +23,6 @@ var parseIPTests = []struct {
 	{"::ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
 	{"::ffff:7f01:0203", IPv4(127, 1, 2, 3)},
 	{"0:0:0:0:0000:ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
-	{"0:0:0:0:000000:ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
 	{"0:0:0:0::ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
 
 	{"2001:4860:0:2001::68", IP{0x20, 0x01, 0x48, 0x60, 0, 0, 0x20, 0x01, 0, 0, 0, 0, 0, 0, 0x00, 0x68}},
@@ -39,6 +38,8 @@ var parseIPTests = []struct {
 	{"fe80::1%lo0", nil},
 	{"fe80::1%911", nil},
 	{"", nil},
+	//6 zeroes in one group
+	{"0:0:0:0:000000:ffff:127.1.2.3", nil},
 	{"a1:a2:a3:a4::b1:b2:b3:b4", nil}, // Issue 6628
 	{"127.001.002.003", nil},
 	{"::ffff:127.001.002.003", nil},