From e17fcc85410a5aa54fb3b227096b4999feaf28fe Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Fri, 1 Nov 2019 19:50:16 +0100
Subject: [PATCH 1/3] dgram: reset bind state before emitting error

This was previously done inconsistently, sometimes before, sometimes
after emitting the event.
---
 lib/dgram.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/dgram.js b/lib/dgram.js
index d29d1e7b190f3a..35d414320a7e43 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -240,8 +240,8 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
       }, (err) => {
         // Callback to handle error.
         const ex = errnoException(err, 'open');
-        this.emit('error', ex);
         state.bindState = BIND_STATE_UNBOUND;
+        this.emit('error', ex);
       });
       return this;
     }
@@ -309,8 +309,8 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
       }, (err) => {
         // Callback to handle error.
         const ex = exceptionWithHostPort(err, 'bind', ip, port);
-        this.emit('error', ex);
         state.bindState = BIND_STATE_UNBOUND;
+        this.emit('error', ex);
       });
     } else {
       if (!state.handle)
@@ -319,8 +319,8 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
       const err = state.handle.bind(ip, port || 0, flags);
       if (err) {
         const ex = exceptionWithHostPort(err, 'bind', ip, port);
-        this.emit('error', ex);
         state.bindState = BIND_STATE_UNBOUND;
+        this.emit('error', ex);
         // Todo: close?
         return;
       }

From 2d8aa6407fa8f098bb57f91dff4803031a426e43 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Fri, 1 Nov 2019 19:50:40 +0100
Subject: [PATCH 2/3] dgram: remove listeners on bind error

This avoids piling up `'listening'` event listeners if
`.bind()` fails repeatedly.

Fixes: https://github.com/nodejs/node/issues/30209
---
 lib/dgram.js                                  | 17 +++++++++--
 test/parallel/test-dgram-bind-error-repeat.js | 28 +++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 test/parallel/test-dgram-bind-error-repeat.js

diff --git a/lib/dgram.js b/lib/dgram.js
index 35d414320a7e43..94f44d520220ff 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -211,8 +211,21 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
 
   state.bindState = BIND_STATE_BINDING;
 
-  if (arguments.length && typeof arguments[arguments.length - 1] === 'function')
-    this.once('listening', arguments[arguments.length - 1]);
+  const cb = arguments.length && arguments[arguments.length - 1];
+  if (typeof cb === 'function') {
+    function removeListeners() {
+      this.removeListener('error', removeListeners);
+      this.removeListener('listening', onListening);
+    }
+
+    function onListening() {
+      removeListeners.call(this);
+      cb.call(this);
+    }
+
+    this.on('error', removeListeners);
+    this.on('listening', onListening);
+  }
 
   if (port instanceof UDP) {
     replaceHandle(this, port);
diff --git a/test/parallel/test-dgram-bind-error-repeat.js b/test/parallel/test-dgram-bind-error-repeat.js
new file mode 100644
index 00000000000000..d0fdae5729b4f2
--- /dev/null
+++ b/test/parallel/test-dgram-bind-error-repeat.js
@@ -0,0 +1,28 @@
+'use strict';
+const common = require('../common');
+const dgram = require('dgram');
+
+// Regression test for https://github.com/nodejs/node/issues/30209
+// No warning should be emitted when re-trying `.bind()` on UDP sockets
+// repeatedly.
+
+process.on('warning', common.mustNotCall());
+
+const reservePortSocket = dgram.createSocket('udp4');
+reservePortSocket.bind(() => {
+  const { port } = reservePortSocket.address();
+
+  const newSocket = dgram.createSocket('udp4');
+
+  let errors = 0;
+  newSocket.on('error', common.mustCall(() => {
+    if (++errors < 20) {
+      const cb = errors === 20 ? common.mustCall() : common.mustNotCall();
+      newSocket.bind(port, cb);
+    } else {
+      newSocket.close();
+      reservePortSocket.close();
+    }
+  }, 20));
+  newSocket.bind(port, common.mustNotCall());
+});

From f603ff405d7253580436b64b4c0ad2bb2a787e12 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Sat, 2 Nov 2019 22:22:33 +0100
Subject: [PATCH 3/3] fixup! dgram: remove listeners on bind error

---
 test/parallel/test-dgram-bind-error-repeat.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/test/parallel/test-dgram-bind-error-repeat.js b/test/parallel/test-dgram-bind-error-repeat.js
index d0fdae5729b4f2..a520d30a519cd2 100644
--- a/test/parallel/test-dgram-bind-error-repeat.js
+++ b/test/parallel/test-dgram-bind-error-repeat.js
@@ -17,8 +17,7 @@ reservePortSocket.bind(() => {
   let errors = 0;
   newSocket.on('error', common.mustCall(() => {
     if (++errors < 20) {
-      const cb = errors === 20 ? common.mustCall() : common.mustNotCall();
-      newSocket.bind(port, cb);
+      newSocket.bind(port, common.mustNotCall());
     } else {
       newSocket.close();
       reservePortSocket.close();