symfony/symfony — pull request #8392 by stloyd (2013-07-01 12:31:54+00:00)
Title: [2.3] Return BC compatibility for DI Container

| Q | A
| ------------- | ---
| Bug fix? | yes
| New feature? | no
| BC breaks? | no
| Deprecations? | no
| Tests pass? | yes
| Fixed tickets | #8347
| License | MIT

When setting service to `null` it's considered as existing instead of removed/reset state which is BC break, more in #8347.