tls: handle cases where the raw socket is destroyed

Ensure that the `'close'` event is emitted on a `TLSSocket` when it is
created from an existing raw `net.Socket` and the raw socket is not
closed cleanly (destroyed).

Refs: nodejs@048e0bec5147
Refs: nodejs#49902 (comment)
Fixes: nodejs#49902
PR-URL: nodejs#49980
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

lib/_tls_wrap.js

@@ -657,10 +657,20 @@ tls_wrap.TLSWrap.prototype.close = function close(cb) {
       cb();
   };
 
-  if (this._parentWrap && this._parentWrap._handle === this._parent) {
-    this._parentWrap.once('close', done);
-    return this._parentWrap.destroy();
+  if (this._parentWrap) {
+    if (this._parentWrap._handle === null) {
+      // The socket handle was already closed.
+      done();
+      return;
+    }
+
+    if (this._parentWrap._handle === this._parent) {
+      this._parentWrap.once('close', done);
+      this._parentWrap.destroy();
+      return;
+    }
   }
+
   return this._parent.close(done);
 };
 

test/parallel/test-tls-socket-close.js

@@ -6,6 +6,7 @@ if (!common.hasCrypto)
 const assert = require('assert');
 const tls = require('tls');
 const net = require('net');
+const Countdown = require('../common/countdown');
 const fixtures = require('../common/fixtures');
 
 const key = fixtures.readKey('agent2-key.pem');
@@ -14,19 +15,28 @@ const cert = fixtures.readKey('agent2-cert.pem');
 let serverTlsSocket;
 const tlsServer = tls.createServer({ cert, key }, (socket) => {
   serverTlsSocket = socket;
+  socket.on('close', dec);
 });
 
 // A plain net server, that manually passes connections to the TLS
-// server to be upgraded
+// server to be upgraded.
 let netSocket;
+let netSocketCloseEmitted = false;
 const netServer = net.createServer((socket) => {
-  tlsServer.emit('connection', socket);
-
   netSocket = socket;
-}).listen(0, common.mustCall(function() {
+  tlsServer.emit('connection', socket);
+  socket.on('close', () => {
+    netSocketCloseEmitted = true;
+    assert.strictEqual(serverTlsSocket.destroyed, true);
+  });
+}).listen(0, common.mustCall(() => {
   connectClient(netServer);
 }));
 
+const countdown = new Countdown(2, () => {
+  netServer.close();
+});
+
 // A client that connects, sends one message, and closes the raw connection:
 function connectClient(server) {
   const clientTlsSocket = tls.connect({
@@ -41,18 +51,22 @@ function connectClient(server) {
       assert(serverTlsSocket);
 
       netSocket.destroy();
+      assert.strictEqual(netSocket.destroyed, true);
 
       setImmediate(() => {
-        assert.strictEqual(netSocket.destroyed, true);
-
+        // Close callbacks are executed after `setImmediate()` callbacks.
+        assert.strictEqual(netSocketCloseEmitted, false);
+        assert.strictEqual(serverTlsSocket.destroyed, false);
         setImmediate(() => {
-          assert.strictEqual(clientTlsSocket.destroyed, true);
-          assert.strictEqual(serverTlsSocket.destroyed, true);
-
-          tlsServer.close();
-          netServer.close();
+          assert.strictEqual(netSocketCloseEmitted, true);
         });
       });
     }));
   }));
+
+  clientTlsSocket.on('close', dec);
+}
+
+function dec() {
+  countdown.dec();
 }