test: add known_issues test for GH-2148

PR-URL: #5920
Refs: #2148
Reviewed-By: Brian White <[email protected]>

Author: Trott

test/known_issues/test-stdout-buffer-flush-on-exit.js

@@ -0,0 +1,20 @@
+'use strict';
+// Refs: https://github.com/nodejs/node/issues/2148
+
+require('../common');
+const assert = require('assert');
+const execSync = require('child_process').execSync;
+
+const longLine = 'foo bar baz quux quuz aaa bbb ccc'.repeat(65536);
+
+if (process.argv[2] === 'child') {
+  process.on('exit', () => {
+    console.log(longLine);
+  });
+  process.exit();
+}
+
+const cmd = `${process.execPath} ${__filename} child`;
+const stdout = execSync(cmd).toString().trim();
+
+assert.strictEqual(stdout, longLine);