code review 163072: net: test and fix support for 0-length datagram packets.

src/pkg/net/server_test.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package net
 
 import (
         "io";
         "os";
         "strings";
@@ skipping 27 matching lines @@
                         break
                 }
                 echodone := make(chan int);
                 go runEcho(fd, echodone);
                 <-echodone;     // make sure Echo stops
                 l.Close();
         }
         done <- 1;
 }
 
-func connect(t *testing.T, network, addr string, zerolen bool) {

[r, 2009/12/02 16:03:36]

zeroLen?  empty? isEmpty?

+func connect(t *testing.T, network, addr string, isEmpty bool) {
         var laddr string;
         if network == "unixgram" {
                 laddr = addr + ".local"
         }
         fd, err := Dial(network, laddr, addr);
         if err != nil {
                 t.Fatalf("net.Dial(%q, %q, %q) = _, %v", network, laddr, addr, err)
         }
         fd.SetReadTimeout(10e6);        // 10ms
 
         var b []byte;
-        if !zerolen {
+        if !isEmpty {
                 b = strings.Bytes("hello, world\n")
         }
         var b1 [100]byte;
 
         n, err := fd.Write(b);
         if n != len(b) {
                 t.Fatalf("fd.Write(%q) = %d, %v", b, n, err)
         }
 
         n, err = fd.Read(&b1);
@@ skipping 59 matching lines @@
                         break
                 }
                 if _, err = c.WriteTo(buf[0:n], addr); err != nil {
                         t.Fatalf("WriteTo %v: %v", addr, err)
                 }
         }
         c.Close();
         done <- 1;
 }
 
-func doTestPacket(t *testing.T, network, listenaddr, dialaddr string, zerolen bool) {

[r, 2009/12/02 16:03:36]

ditto

+func doTestPacket(t *testing.T, network, listenaddr, dialaddr string, isEmpty bool) {
         t.Logf("TestPacket %s %s %s\n", network, listenaddr, dialaddr);
         listening := make(chan string);
         done := make(chan int);
         if network == "udp" {
                 listenaddr += ":0"      // any available port
         }
         go runPacket(t, network, listenaddr, listening, done);
         addr := <-listening;    // wait for server to start
         if network == "udp" {
                 dialaddr += addr[strings.LastIndex(addr, ":"):]
         }
-        connect(t, network, dialaddr, zerolen);
+        connect(t, network, dialaddr, isEmpty);
         <-done; // tell server to stop
         <-done; // wait for stop
 }
 
 func TestUDPServer(t *testing.T) {
-        for i := 0; i < 2; i++ {
-                doTestPacket(t, "udp", "0.0.0.0", "127.0.0.1", i > 0);
-                doTestPacket(t, "udp", "", "127.0.0.1", i > 0);

[r, 2009/12/02 16:03:36]

looks to me like what you want to pass is not i > 0 but i.

+        for _, isEmpty := range []bool{false, true} {
+                doTestPacket(t, "udp", "0.0.0.0", "127.0.0.1", isEmpty);
+                doTestPacket(t, "udp", "", "127.0.0.1", isEmpty);
                 if kernelSupportsIPv6() {
-                        doTestPacket(t, "udp", "[::]", "[::ffff:127.0.0.1]", i > 0);
-                        doTestPacket(t, "udp", "[::]", "127.0.0.1", i > 0);
-                        doTestPacket(t, "udp", "0.0.0.0", "[::ffff:127.0.0.1]", i > 0);
+                        doTestPacket(t, "udp", "[::]", "[::ffff:127.0.0.1]", isEmpty);
+                        doTestPacket(t, "udp", "[::]", "127.0.0.1", isEmpty);
+                        doTestPacket(t, "udp", "0.0.0.0", "[::ffff:127.0.0.1]", isEmpty);
                 }
         }
 }
 
 func TestUnixDatagramServer(t *testing.T) {
-        for i := 0; i < 2; i++ {
+        for _, isEmpty := range []bool{false, true} {
                 os.Remove("/tmp/gotest1.net");
                 os.Remove("/tmp/gotest1.net.local");
-                doTestPacket(t, "unixgram", "/tmp/gotest1.net", "/tmp/gotest1.net", i > 0);
+                doTestPacket(t, "unixgram", "/tmp/gotest1.net", "/tmp/gotest1.net", isEmpty);
                 os.Remove("/tmp/gotest1.net");
                 os.Remove("/tmp/gotest1.net.local");
                 if syscall.OS == "linux" {
                         // Test abstract unix domain socket, a Linux-ism
-                        doTestPacket(t, "unixgram", "@gotest1/net", "@gotest1/net", i > 0)
+                        doTestPacket(t, "unixgram", "@gotest1/net", "@gotest1/net", isEmpty)
                 }
         }
 }