http: don't destroy socket after request completes

lib/_http_client.js

@@ -698,6 +698,14 @@ ClientRequest.prototype.destroy = function destroy(err) {
     this.res._dump();
   }
 
+  // Nothing left to cancel: the request was fully sent and the response was
+  // fully received. Destroying the socket here would emit an error on a
+  // socket that is already being released to the agent, at which point
+  // socketErrorListener has been removed and nothing would handle it.
+  if (this.writableFinished && this.res?.complete) {
+    return this;
+  }
+
   this[kError] = err;
   this.socket?.destroy(err);
 

test/parallel/test-http-client-abort-completed-keepalive.js

@@ -0,0 +1,57 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+
+// Aborting a request whose exchange has already completed must not destroy the
+// socket that is being released to the agent. socketErrorListener has been
+// removed by responseKeepAlive() at that point, so the error would be emitted
+// on a socket with no 'error' listener and crash the process.
+// Refs: https://github.com/nodejs/node/issues/65938
+
+const agent = new http.Agent({ keepAlive: true });
+
+const server = http.createServer((req, res) => {
+  res.end('x');
+});
+
+server.listen(0, '127.0.0.1', common.mustCall(() => {
+  const controller = new AbortController();
+
+  const req = http.get({
+    port: server.address().port,
+    host: '127.0.0.1',
+    agent,
+    signal: controller.signal,
+  }, common.mustCall(async (res) => {
+    res.on('error', common.mustNotCall());
+
+    for await (const chunk of res) {
+      assert.strictEqual(chunk.length, 1);
+      assert.strictEqual(res.complete, true);
+      assert.strictEqual(req.writableFinished, true);
+      controller.abort(new Error('stop reading'));
+      break;
+    }
+
+    // The socket must survive the abort and go back to the pool, and a
+    // subsequent request must be able to reuse it.
+    const res2 = await new Promise((resolve, reject) => {
+      const req2 = http.get({
+        port: server.address().port,
+        host: '127.0.0.1',
+        agent,
+      }, resolve);
+      req2.on('error', reject);
+    });
+
+    let body = '';
+    for await (const chunk of res2) body += chunk;
+    assert.strictEqual(body, 'x');
+
+    agent.destroy();
+    server.close();
+  }));
+
+  req.on('error', common.mustNotCall());
+}));