"Installments not valid" even with installments disabled

[galdiuz]

Magento version: 2.2.8
Plugin version: 2.4.3 (tested, but would probably appear in 4.0.2 as well)
Description:
If installments has been enabled for credit card payment and is later disabled the value saved for payment/adyen_cc/installments will be a:0:{}. This means that in Gateway/Validator/InstallmentValidator.php the validation on row 82 can succeed even though installments is disabled in the config, as $installmentsAvailable would be "a:0:{}" and PHP strings are truthy.

76 $installmentsAvailable = $this->adyenHelper->getAdyenCcConfigData('installments');
77 $installmentSelected = $payment->getAdditionalInformation('number_of_installments');
78 $ccType = $payment->getAdditionalInformation('cc_type');
79 if ($installmentsAvailable) {
80     $installments = unserialize($installmentsAvailable);
81 }
82 if ($installmentSelected && $installmentsAvailable) {

Proposed solution is to also check payment/adyen_cc/enable_installments. See diff below:

diff --git a/Gateway/Validator/InstallmentValidator.php b/Gateway/Validator/InstallmentValidator.php
index 5a90520..59db8e7 100644
--- a/Gateway/Validator/InstallmentValidator.php
+++ b/Gateway/Validator/InstallmentValidator.php
@@ -70,7 +70,8 @@ class InstallmentValidator extends AbstractValidator
         $fails = [];
         $payment = $validationSubject['payment'];
         $quote = $this->session->getQuote();
-        if ($quote) {
+        $installmentsEnabled = $this->adyenHelper->getAdyenCcConfigData('enable_installments');
+        if ($quote && $installmentsEnabled) {
             $grandTotal = $quote->getGrandTotal();
             $installmentsAvailable = $this->adyenHelper->getAdyenCcConfigData('installments');
             $installmentSelected = $payment->getAdditionalInformation('number_of_installments');

[cyattilakiss]

Hi @galdiuz ,

Thank you for raising this issue, we are going to look at the suggested solution asap.

Best,
Attila
Adyen

[cyattilakiss]

Hi @galdiuz ,

We are going to merge the fix soon. Thank you for raising the issue and suggestions the solution.
Best,
Attila
Adyen

[cyattilakiss]

hi @galdiuz ,
The changes are released in the https://github.com/Adyen/adyen-magento2/releases/tag/4.0.3 version.
Best,
Attila
Adyen