symfony/symfony — pull request #13085 by xphere (2014-12-23 12:18:01+00:00)
Title: [FrameworkBundle] Fix dependency on ExtensionInterface over implementation

| Q | A
| ------------- | ---
| Bug fix? | yes
| New feature? | no
| BC breaks? | no
| Deprecations? | no
| Tests pass? | no (but anyway, they didn't pass previously)
| Fixed tickets | #13084
| License | MIT

When implementing `ExtensionInterface` through classes not inheriting the core `Extension`, the command `config:dump` throws.
This bug was introduced in 2.5 and could be fixed up to 2.7 with the same patch.