repl: handle exceptions from async context after close

lib/repl.js

@@ -195,7 +195,12 @@ function setupExceptionCapture() {
 
   process.addUncaughtExceptionCaptureCallback((err) => {
     const store = replContext.getStore();
-    if (store?.replServer && !store.replServer.closed) {
+    // TODO(addaleax): Add back a `store.replServer.closed` check here
+    // as a semver-major change.
+    // This check may need to allow for an opt-out, since the change in
+    // behavior could lead to DoS vulnerabilities (e.g. in the case of
+    // the net-based REPL described in our docs).
+    if (store?.replServer) {
       store.replServer._handleError(err);
       return true; // We handled it
     }

test/parallel/test-repl-uncaught-exception-after-input-ended.js

@@ -0,0 +1,23 @@
+'use strict';
+const common = require('../common');
+const { start } = require('node:repl');
+const { PassThrough } = require('node:stream');
+const assert = require('node:assert');
+
+// This test verifies that uncaught exceptions in the REPL
+// do not bring down the process, even if stdin may already
+// have been ended at that point (and the REPL closed as
+// a result of that).
+const input = new PassThrough();
+const output = new PassThrough().setEncoding('utf8');
+start({
+  input,
+  output,
+  terminal: false,
+});
+
+input.end('setImmediate(() => { throw new Error("test"); });\n');
+
+setImmediate(common.mustCall(() => {
+  assert.match(output.read(), /Uncaught Error: test/);
+}));