bug #29755 Improved BIC + IBAN validator for some special cases (javiereguiluz)

This PR was squashed before being merged into the 4.3-dev branch (closes #29755).

Discussion
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Improved BIC + IBAN validator for some special cases

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

While blogging about [Improved Financial Constraints in Symfony 4.3](https://symfony.com/blog/new-in-symfony-4-3-improved-financial-constraints) I found this resource that mentions some exceptions when validating BIC + IBAN: https://wiki.xmldation.com/index.php?title=Support/EPC/IBAN_%26_BIC_relation

I don't know if that resource is fully reliable ... but I checked it in the official "European Banking Resources" website (https://www.ecbs.org/iban/) and most of it matches, so I think we can safely make this change.

Commits
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88a1696 Improved BIC + IBAN validator for some special cases

Author: nicolas-grekas

src/Symfony/Component/Validator/Constraints/BicValidator.php

@@ -29,6 +29,25 @@
  */
 class BicValidator extends ConstraintValidator
 {
+    private const BIC_COUNTRY_TO_IBAN_COUNTRY_MAP = array(
+        // Reference: https://www.ecbs.org/iban/france-bank-account-number.html
+        'GF' => 'FR', // French Guiana
+        'PF' => 'FR', // French Polynesia
+        'TF' => 'FR', // French Southern Territories
+        'GP' => 'FR', // Guadeloupe
+        'MQ' => 'FR', // Martinique
+        'YT' => 'FR', // Mayotte
+        'NC' => 'FR', // New Caledonia
+        'RE' => 'FR', // Reunion
+        'PM' => 'FR', // Saint Pierre and Miquelon
+        'WF' => 'FR', // Wallis and Futuna Islands
+        // Reference: https://www.ecbs.org/iban/united-kingdom-uk-bank-account-number.html
+        'JE' => 'GB', // Jersey
+        'IM' => 'GB', // Isle of Man
+        'GG' => 'GB', // Guernsey
+        'VG' => 'GB', // British Virgin Islands
+    );
+
     private $propertyAccessor;
 
     public function __construct(PropertyAccessor $propertyAccessor = null)
@@ -126,7 +145,7 @@ public function validate($value, Constraint $constraint)
             return;
         }
         $ibanCountryCode = substr($iban, 0, 2);
-        if (ctype_alpha($ibanCountryCode) && substr($canonicalize, 4, 2) !== $ibanCountryCode) {
+        if (ctype_alpha($ibanCountryCode) && !$this->bicAndIbanCountriesMatch(substr($canonicalize, 4, 2), $ibanCountryCode)) {
             $this->context->buildViolation($constraint->ibanMessage)
                 ->setParameter('{{ value }}', $this->formatValue($value))
                 ->setParameter('{{ iban }}', $iban)
@@ -146,4 +165,9 @@ private function getPropertyAccessor(): PropertyAccessor
 
         return $this->propertyAccessor;
     }
+
+    private function bicAndIbanCountriesMatch(string $bicCountryCode, string $ibanCountryCode): bool
+    {
+        return $ibanCountryCode === $bicCountryCode || $ibanCountryCode === (self::BIC_COUNTRY_TO_IBAN_COUNTRY_MAP[$bicCountryCode] ?? null);
+    }
 }

src/Symfony/Component/Validator/Tests/Constraints/BicValidatorTest.php

@@ -221,6 +221,41 @@ public function getInvalidBics()
             array('DEUTAT2lxxx', Bic::INVALID_CASE_ERROR),
         );
     }
+
+    /**
+     * @dataProvider getValidBicSpecialCases
+     *
+     * Some territories have their own ISO country code but can use another country code
+     * for IBAN accounts. Example: "French Guiana" (country code "GF") can use FR too.
+     */
+    public function testValidBicSpecialCases(string $bic, string $iban)
+    {
+        $constraint = new Bic(array('iban' => $iban));
+        $this->validator->validate($bic, $constraint);
+
+        $this->assertNoViolation();
+    }
+
+    public function getValidBicSpecialCases()
+    {
+        // FR related special cases
+        yield array('BNPAGFGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAPFGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPATFGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAGPGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAMQGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAYTGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPANCGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAREGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAPMGX', 'FR14 2004 1010 0505 0001 3M02 606');
+        yield array('BNPAWFGX', 'FR14 2004 1010 0505 0001 3M02 606');
+
+        // GB related special cases
+        yield array('BARCJESA', 'GB12 CPBK 0892 9965 0449 911');
+        yield array('BARCIMSA', 'GB12 CPBK 0892 9965 0449 911');
+        yield array('BARCGGSA', 'GB12 CPBK 0892 9965 0449 911');
+        yield array('BARCVGSA', 'GB12 CPBK 0892 9965 0449 911');
+    }
 }
 
 class BicComparisonTestClass