bug #22109 [Validator] check for empty host when calling checkdnsrr() (apetitpa)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #22109).

Discussion
----------

[Validator] check for empty host when calling checkdnsrr()

| Q | A |
| --- | --- |
| Branch? | master|
| Bug fix? | yes |
| New feature? | no |
| BC breaks? | no |
| Deprecations? | no |
| Tests pass? | yes |
| Fixed tickets | #22106 |
| License | MIT |
| Doc PR | n/a |

This should fix the email validator issue

Commits
-------

7104c4e849 move provider after test
c07fb416ff update dataProvider function name
1825d0f2ae cast substr result to string and remove empty function use
894127bf09 rename dataset provider
d973eb1f7d Add a test to prevent future regressions
6f24b05467 Switch to `empty` native function to check emptiness
f390f29173 remove non relevant test case
91b665c12a Switch to `is_string` native method
6071ff6c8f Remove unnecessary parentheses
9753a2773e Add a test case to prevent future regressions
4fcb24bacb Move empty condition in return statement
a090ef855a Use LF line separator
60392fdd43 fix coding standard to comply with fabbot
197d19f34c Remove malformed EmailValidatorTest + Update UrlValidator test
6b0702e52a Add empty check on host in other methods + add unit tests
6dd023f255 [Validator] Allow checkMX() to return false when $host is empty

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

@@ -93,7 +93,7 @@ class EmailValidator extends ConstraintValidator
             return;
         }
 
-        $host = substr($value, strrpos($value, '@') + 1);
+        $host = (string) substr($value, strrpos($value, '@') + 1);
 
         // Check for host DNS resource records
         if ($constraint->checkMX) {
@@ -138,7 +138,7 @@ class EmailValidator extends ConstraintValidator
      */
     private function checkMX($host)
     {
-        return checkdnsrr($host, 'MX');
+        return '' !== $host && checkdnsrr($host, 'MX');
     }
 
     /**
@@ -150,6 +150,6 @@ class EmailValidator extends ConstraintValidator
      */
     private function checkHost($host)
     {
-        return $this->checkMX($host) || (checkdnsrr($host, 'A') || checkdnsrr($host, 'AAAA'));
+        return '' !== $host && ($this->checkMX($host) || (checkdnsrr($host, 'A') || checkdnsrr($host, 'AAAA')));
     }
 }

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

@@ -80,7 +80,7 @@ class UrlValidator extends ConstraintValidator
         if ($constraint->checkDNS) {
             $host = parse_url($value, PHP_URL_HOST);
 
-            if (!checkdnsrr($host, 'ANY')) {
+            if (!is_string($host) || !checkdnsrr($host, 'ANY')) {
                 if ($this->context instanceof ExecutionContextInterface) {
                     $this->context->buildViolation($constraint->dnsMessage)
                        ->setParameter('{{ value }}', $this->formatValue($host))

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

@@ -159,4 +159,32 @@ class EmailValidatorTest extends AbstractConstraintValidatorTest
 
         $this->assertNoViolation();
     }
+
+    /**
+     * @dataProvider provideCheckTypes
+     */
+    public function testEmptyHostIsNotValid($checkType, $violation)
+    {
+        $this->validator->validate(
+            'foo@bar.fr@',
+            new Email(array(
+                'message' => 'myMessage',
+                $checkType => true,
+            ))
+        );
+
+        $this
+            ->buildViolation('myMessage')
+            ->setParameter('{{ value }}', '"foo@bar.fr@"')
+            ->setCode($violation)
+            ->assertRaised();
+    }
+
+    public function provideCheckTypes()
+    {
+        return array(
+            array('checkMX', Email::MX_CHECK_FAILED_ERROR),
+            array('checkHost', Email::HOST_CHECK_FAILED_ERROR),
+        );
+    }
 }

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

@@ -171,6 +171,7 @@ class UrlValidatorTest extends AbstractConstraintValidatorTest
             array('http://example.com/exploit.html?<script>alert(1);</script>'),
             array('http://example.com/exploit.html?hel lo'),
             array('http://example.com/exploit.html?not_a%hex'),
+            array('http://'),
         );
     }