From ad341843a7661e4883c8a66b12433e55db1dfc7e Mon Sep 17 00:00:00 2001
From: =?utf8?q?Michael=20Teichgr=C3=A4ber?= <mteichgraeber@gmx.de>
Date: Wed, 30 Jan 2013 09:25:16 -0800
Subject: [PATCH] net: SplitHostPort: adjust error message for missing port in
 IPv6 addresses

An hostport of "[::1]" now results in the same error message
"missing port in address" as the hostport value "127.0.0.1",
so SplitHostPort won't complain about "too many colons
in address" anymore for an IPv6 address missing a port.

Added tests checking the error values.

Fixes #4526.

R=dave, rsc, mikioh.mikioh
CC=golang-dev
https://golang.org/cl/7038045
---
 src/pkg/net/ip_test.go | 32 ++++++++++++++++++++++++
 src/pkg/net/ipsock.go  | 57 +++++++++++++++++++++++++++++++++++-------
 2 files changed, 80 insertions(+), 9 deletions(-)

diff --git a/src/pkg/net/ip_test.go b/src/pkg/net/ip_test.go
index 8324d2a327..f8b7f067fa 100644
--- a/src/pkg/net/ip_test.go
+++ b/src/pkg/net/ip_test.go
@@ -269,6 +269,28 @@ var splitjointests = []struct {
 	{"127.0.0.1", "1234", "127.0.0.1:1234"},
 	{"::1", "80", "[::1]:80"},
 	{"google.com", "https%foo", "google.com:https%foo"}, // Go 1.0 behavior
+	{"", "0", ":0"},
+	{"127.0.0.1", "", "127.0.0.1:"},           // Go 1.0 behaviour
+	{"www.google.com", "", "www.google.com:"}, // Go 1.0 behaviour
+}
+
+var splitfailuretests = []struct {
+	HostPort string
+	Err      string
+}{
+	{"www.google.com", "missing port in address"},
+	{"127.0.0.1", "missing port in address"},
+	{"[::1]", "missing port in address"},
+	{"::1", "too many colons in address"},
+
+	// Test cases that didn't fail in Go 1.0
+	{"[foo:bar]", "missing port in address"},
+	{"[foo:bar]baz", "missing port in address"},
+	{"[foo]:[bar]:baz", "too many colons in address"},
+	{"[foo]bar:baz", "missing port in address"},
+	{"[foo]:[bar]baz", "unexpected '[' in address"},
+	{"foo[bar]:baz", "unexpected '[' in address"},
+	{"foo]bar:baz", "unexpected ']' in address"},
 }
 
 func TestSplitHostPort(t *testing.T) {
@@ -277,6 +299,16 @@ func TestSplitHostPort(t *testing.T) {
 			t.Errorf("SplitHostPort(%q) = %q, %q, %v; want %q, %q, nil", tt.Join, host, port, err, tt.Host, tt.Port)
 		}
 	}
+	for _, tt := range splitfailuretests {
+		if _, _, err := SplitHostPort(tt.HostPort); err == nil {
+			t.Errorf("SplitHostPort(%q) should have failed", tt.HostPort)
+		} else {
+			e := err.(*AddrError)
+			if e.Err != tt.Err {
+				t.Errorf("SplitHostPort(%q) = _, _, %q; want %q", tt.HostPort, e.Err, tt.Err)
+			}
+		}
+	}
 }
 
 func TestJoinHostPort(t *testing.T) {
diff --git a/src/pkg/net/ipsock.go b/src/pkg/net/ipsock.go
index 5636c85b4f..1ef4892896 100644
--- a/src/pkg/net/ipsock.go
+++ b/src/pkg/net/ipsock.go
@@ -77,23 +77,62 @@ func SplitHostPort(hostport string) (host, port string, err error) {
 }
 
 func splitHostPort(hostport string) (host, port, zone string, err error) {
+	j, k := 0, 0
+
 	// The port starts after the last colon.
 	i := last(hostport, ':')
 	if i < 0 {
-		err = &AddrError{"missing port in address", hostport}
-		return
+		goto missingPort
 	}
-	host, port = hostport[:i], hostport[i+1:]
-	// Can put brackets around host ...
-	if len(host) > 0 && host[0] == '[' && host[len(host)-1] == ']' {
-		host = host[1 : len(host)-1]
+
+	if hostport[0] == '[' {
+		// Expect the first ']' just before the last ':'.
+		end := byteIndex(hostport, ']')
+		if end < 0 {
+			err = &AddrError{"missing ']' in address", hostport}
+			return
+		}
+		switch end + 1 {
+		case len(hostport):
+			// There can't be a ':' behind the ']' now.
+			goto missingPort
+		case i:
+			// The expected result.
+		default:
+			// Either ']' isn't followed by a colon, or it is
+			// followed by a colon that is not the last one.
+			if hostport[end+1] == ':' {
+				goto tooManyColons
+			}
+			goto missingPort
+		}
+		host = hostport[1:end]
+		j, k = 1, end+1 // there can't be a '[' resp. ']' before these positions
 	} else {
-		// ... but if there are no brackets, no colons.
+		host = hostport[:i]
+
 		if byteIndex(host, ':') >= 0 {
-			err = &AddrError{"too many colons in address", hostport}
-			return
+			goto tooManyColons
 		}
 	}
+	if byteIndex(hostport[j:], '[') >= 0 {
+		err = &AddrError{"unexpected '[' in address", hostport}
+		return
+	}
+	if byteIndex(hostport[k:], ']') >= 0 {
+		err = &AddrError{"unexpected ']' in address", hostport}
+		return
+	}
+
+	port = hostport[i+1:]
+	return
+
+missingPort:
+	err = &AddrError{"missing port in address", hostport}
+	return
+
+tooManyColons:
+	err = &AddrError{"too many colons in address", hostport}
 	return
 }
 
-- 
2.48.1