http: fix request when setHost is true

Fixes: https://github.com/nodejs/node/issues/19457

PR-URL: https://github.com/nodejs/node/pull/19502
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

doc/api/http.md

@@ -1858,6 +1858,8 @@ changes:
     details. Any [`Duplex`][] stream is a valid return value.
   * `timeout` {number}: A number specifying the socket timeout in milliseconds.
     This will set the timeout before the socket is connected.
+  * `setHost` {boolean}: Specifies whether or not to automatically add the
+    `Host` header. Defaults to `true`.
 * `callback` {Function}
 * Returns: {http.ClientRequest}
 

lib/_http_client.js

@@ -116,7 +116,7 @@ function ClientRequest(options, cb) {
   var host = options.host = validateHost(options.hostname, 'hostname') ||
                             validateHost(options.host, 'host') || 'localhost';
 
-  var setHost = (options.setHost === undefined);
+  var setHost = (options.setHost === undefined || Boolean(options.setHost));
 
   this.socketPath = options.socketPath;
   this.timeout = options.timeout;

test/parallel/test-https-host-headers.js

@@ -16,7 +16,7 @@ const httpsServer = https.createServer(options, reqHandler);
 
 function reqHandler(req, res) {
   console.log(`Got request: ${req.headers.host} ${req.url}`);
-  if (req.url === '/setHostFalse5') {
+  if (req.url.startsWith('/setHostFalse')) {
     assert.strictEqual(req.headers.host, undefined);
   } else {
     assert.strictEqual(
@@ -97,6 +97,34 @@ function testHttps() {
       setHost: false,
       port: this.address().port,
       rejectUnauthorized: false
+    }, cb).on('error', thrower);
+
+    https.request({
+      method: 'GET',
+      path: `/${counter++}`,
+      host: 'localhost',
+      setHost: true,
+      //agent: false,
+      port: this.address().port,
+      rejectUnauthorized: false
     }, cb).on('error', thrower).end();
+
+    https.get({
+      method: 'GET',
+      path: `/setHostFalse${counter++}`,
+      host: 'localhost',
+      setHost: 0,
+      port: this.address().port,
+      rejectUnauthorized: false
+    }, cb).on('error', thrower);
+
+    https.get({
+      method: 'GET',
+      path: `/setHostFalse${counter++}`,
+      host: 'localhost',
+      setHost: null,
+      port: this.address().port,
+      rejectUnauthorized: false
+    }, cb).on('error', thrower);
   });
 }