http2: remove square brackets from parsed hostname

Make `http2.connect()` work when using URLs with literal IPv6
addresses.

Fixes: https://github.com/nodejs/node/issues/28216

PR-URL: https://github.com/nodejs/node/pull/28406
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

lib/internal/http2/core.js

@@ -2778,7 +2778,16 @@ function connect(authority, options, listener) {
   const protocol = authority.protocol || options.protocol || 'https:';
   const port = '' + (authority.port !== '' ?
     authority.port : (authority.protocol === 'http:' ? 80 : 443));
-  const host = authority.hostname || authority.host || 'localhost';
+  let host = 'localhost';
+
+  if (authority.hostname) {
+    host = authority.hostname;
+
+    if (host[0] === '[')
+      host = host.slice(1, -1);
+  } else if (authority.host) {
+    host = authority.host;
+  }
 
   let socket;
   if (typeof options.createConnection === 'function') {

test/parallel/test-http2-connect.js

@@ -1,6 +1,12 @@
 'use strict';
 
-const { mustCall, hasCrypto, skip, expectsError } = require('../common');
+const {
+  mustCall,
+  hasCrypto,
+  hasIPv6,
+  skip,
+  expectsError
+} = require('../common');
 if (!hasCrypto)
   skip('missing crypto');
 const { createServer, connect } = require('http2');
@@ -73,3 +79,25 @@ const { connect: netConnect } = require('net');
     type: Error
   });
 }
+
+// Check for literal IPv6 addresses in URL's
+if (hasIPv6) {
+  const server = createServer();
+  server.listen(0, '::1', mustCall(() => {
+    const { port } = server.address();
+    const clients = new Set();
+
+    clients.add(connect(`http://[::1]:${port}`));
+    clients.add(connect(new URL(`http://[::1]:${port}`)));
+
+    for (const client of clients) {
+      client.once('connect', mustCall(() => {
+        client.close();
+        clients.delete(client);
+        if (clients.size === 0) {
+          server.close();
+        }
+      }));
+    }
+  }));
+}