From ceb13773adb2282d22606f884e3d587f51f56c7e Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Wed, 21 Oct 2015 13:52:04 +0200
Subject: [PATCH] debugger: propagate --debug-port= to debuggee

Before this commit `node --debug-port=1234 debug t.js` ignored the
--debug-port= argument, binding to the default port 5858 instead,
making it impossible to debug more than one process on the same
machine that way.

This commit also reduces the number of places where the default port
is hard-coded by one.

Fixes: https://github.com/nodejs/node/issues/3345
PR-URL: https://github.com/nodejs/node/pull/3470
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/_debugger.js                         |  4 +--
 test/parallel/test-debug-port-numbers.js | 41 ++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 test/parallel/test-debug-port-numbers.js

diff --git a/lib/_debugger.js b/lib/_debugger.js
index 411db79d087798..a5d3f6e87262c5 100644
--- a/lib/_debugger.js
+++ b/lib/_debugger.js
@@ -25,7 +25,7 @@ exports.start = function(argv, stdin, stdout) {
   stdin = stdin || process.stdin;
   stdout = stdout || process.stdout;
 
-  const args = ['--debug-brk'].concat(argv);
+  const args = [`--debug-brk=${exports.port}`].concat(argv);
   const interface_ = new Interface(stdin, stdout, args);
 
   stdin.resume();
@@ -40,7 +40,7 @@ exports.start = function(argv, stdin, stdout) {
   });
 };
 
-exports.port = 5858;
+exports.port = process.debugPort;
 
 
 //
diff --git a/test/parallel/test-debug-port-numbers.js b/test/parallel/test-debug-port-numbers.js
new file mode 100644
index 00000000000000..e21cb72f0a0622
--- /dev/null
+++ b/test/parallel/test-debug-port-numbers.js
@@ -0,0 +1,41 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const path = require('path');
+const spawn = require('child_process').spawn;
+
+const children = [];
+for (let i = 0; i < 4; i += 1) {
+  const port = common.PORT + i;
+  const args = [`--debug-port=${port}`, '--interactive', 'debug', __filename];
+  const child = spawn(process.execPath, args, { stdio: 'pipe' });
+  child.test = { port: port, stdout: '' };
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', function(s) { child.test.stdout += s; update(); });
+  child.stdout.pipe(process.stdout);
+  child.stderr.pipe(process.stderr);
+  children.push(child);
+}
+
+function update() {
+  // Debugger prints relative paths except on Windows.
+  const filename = path.basename(__filename);
+
+  let ready = 0;
+  for (const child of children)
+    ready += RegExp(`break in .*?${filename}:1`).test(child.test.stdout);
+
+  if (ready === children.length)
+    for (const child of children)
+      child.kill();
+}
+
+process.on('exit', function() {
+  for (const child of children) {
+    const one = RegExp(`Debugger listening on port ${child.test.port}`);
+    const two = RegExp(`connecting to 127.0.0.1:${child.test.port}`);
+    assert(one.test(child.test.stdout));
+    assert(two.test(child.test.stdout));
+  }
+});