bug #14853 [Validator] more strict e-mail validation regex (xabbuh)

This PR was merged into the 2.6 branch.

Discussion
----------

[Validator] more strict e-mail validation regex

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #14848
| License       | MIT
| Doc PR        |

Commits
-------

6491033 [Validator] more strict e-mail validation regex

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

@@ -24,8 +24,6 @@ use Symfony\Component\Validator\Exception\UnexpectedTypeException;
 class EmailValidator extends ConstraintValidator
 {
     /**
-     * isStrict
-     *
      * @var bool
      */
     private $isStrict;
@@ -73,7 +71,7 @@ class EmailValidator extends ConstraintValidator
 
                 return;
             }
-        } elseif (!preg_match('/.+\@.+\..+/', $value)) {
+        } elseif (!preg_match('/^.+\@\S+\.\S+$/', $value)) {
             $this->buildViolation($constraint->message)
                 ->setParameter('{{ value }}', $this->formatValue($value))
                 ->setCode(Email::INVALID_FORMAT_ERROR)

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

@@ -91,6 +91,7 @@ class EmailValidatorTest extends AbstractConstraintValidatorTest
             array('example'),
             array('example@'),
             array('example@localhost'),
+            array('foo@example.com bar'),
         );
     }