symfony/symfony — pull request #11709 by tommygnr (2014-08-19 15:50:07+00:00)
Title: Expression validator

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

The ExpressionValidator was incorrectly skipping validation of null or empty string values.

For example the following was (incorrectly) considered valid if hairColour is null because the validator was skipped
```php