src: fix crypto.privateEncrypt fails first time

src/crypto/crypto_keys.cc

@@ -318,6 +318,7 @@ MaybeLocal<Value> WritePrivateKey(
     }
   }
 
+  MarkPopErrorOnReturn mark_pop_error_on_return;
   bool err;
 
   PKEncodingType encoding_type = config.type_.ToChecked();

test/parallel/test-crypto-publicDecrypt-fails-first-time.js

@@ -0,0 +1,37 @@
+'use strict';
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+// Test for https://github.com/nodejs/node/issues/40814
+
+const assert = require('assert');
+const crypto = require('crypto');
+
+const { privateKey, publicKey } = crypto.generateKeyPairSync('rsa', {
+  modulusLength: 2048,
+  publicKeyEncoding: {
+    type: 'spki',
+    format: 'pem'
+  },
+  privateKeyEncoding: {
+    type: 'pkcs8',
+    format: 'pem',
+    cipher: 'aes-128-ecb',
+    passphrase: 'abcdef'
+  }
+});
+assert.notStrictEqual(privateKey.toString(), '');
+
+const msg = 'The quick brown fox jumps over the lazy dog';
+
+const encryptedString = crypto.privateEncrypt({
+  key: privateKey,
+  passphrase: 'abcdef'
+}, Buffer.from(msg)).toString('base64');
+const decryptedString = crypto.publicDecrypt(publicKey, Buffer.from(encryptedString, 'base64')).toString();
+console.log(`Encrypted: ${encryptedString}`);
+console.log(`Decrypted: ${decryptedString}`);
+
+assert.notStrictEqual(encryptedString, '');
+assert.strictEqual(decryptedString, msg);