net: use cached peername to resolve remote fields

Allows socket.remote* properties to still be accessed even after the
socket is closed.

Fixes: https://github.com/joyent/node/issues/9287
PR-URL: https://github.com/joyent/node/pull/9366
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

lib/net.js

@@ -556,10 +556,10 @@ function onread(nread, buffer) {
 
 
 Socket.prototype._getpeername = function() {
-  if (!this._handle || !this._handle.getpeername) {
-    return {};
-  }
   if (!this._peername) {
+    if (!this._handle || !this._handle.getpeername) {
+      return {};
+    }
     var out = {};
     var err = this._handle.getpeername(out);
     if (err) return {};  // FIXME(bnoordhuis) Throw?
@@ -865,6 +865,7 @@ Socket.prototype.connect = function(options, cb) {
     this._writableState.errorEmitted = false;
     this.destroyed = false;
     this._handle = null;
+    this._peername = null;
   }
 
   var self = this;

test/parallel/test-net-remote-address-port.js

@@ -20,6 +20,10 @@ var server = net.createServer(function(socket) {
   socket.on('end', function() {
     if (++conns_closed == 2) server.close();
   });
+  socket.on('close', function() {
+    assert.notEqual(-1, remoteAddrCandidates.indexOf(socket.remoteAddress));
+    assert.notEqual(-1, remoteFamilyCandidates.indexOf(socket.remoteFamily));
+  });
   socket.resume();
 });
 
@@ -32,12 +36,20 @@ server.listen(common.PORT, 'localhost', function() {
     assert.equal(common.PORT, client.remotePort);
     client.end();
   });
+  client.on('close', function() {
+    assert.notEqual(-1, remoteAddrCandidates.indexOf(client.remoteAddress));
+    assert.notEqual(-1, remoteFamilyCandidates.indexOf(client.remoteFamily));
+  });
   client2.on('connect', function() {
     assert.notEqual(-1, remoteAddrCandidates.indexOf(client2.remoteAddress));
     assert.notEqual(-1, remoteFamilyCandidates.indexOf(client2.remoteFamily));
     assert.equal(common.PORT, client2.remotePort);
     client2.end();
   });
+  client2.on('close', function() {
+    assert.notEqual(-1, remoteAddrCandidates.indexOf(client2.remoteAddress));
+    assert.notEqual(-1, remoteFamilyCandidates.indexOf(client2.remoteFamily));
+  });
 });
 
 process.on('exit', function() {