net: do not add multiple connect and finish listeners when multiple Socket.destroySoon's were scheduled

lib/net.js

@@ -795,13 +795,20 @@ function onReadableStreamEnd() {
 
 
 Socket.prototype.destroySoon = function() {
+  if (this.destroyingOnFinish) return;
+
   if (this.writable)
     this.end();
 
   if (this.writableFinished)
     this.destroy();
-  else
-    this.once('finish', this.destroy);
+  else {
+    this.destroyingOnFinish = true;
+    this.once('finish', () => {
+      this.destroyingOnFinish = false;
+      this.destroy();
+    });
+  }
 };
 
 

test/parallel/test-net-socket-not-duplicates-destroy-soon-listeners.js

@@ -0,0 +1,15 @@
+'use strict';
+require('../common');
+const { addresses } = require('../common/internet');
+
+const assert = require('assert');
+const { Socket } = require('net');
+
+const socket = new Socket();
+socket.on('error', () => {
+  // noop
+});
+socket.connect({ host: addresses.INVALID_HOST, port: 1234 });
+socket.destroySoon();
+socket.destroySoon();
+assert.strictEqual(socket.listeners('finish').length, 1);