symfony/symfony — pull request #4180 by shieldo (2012-05-02 10:52:57+00:00)
Title: [Form] made ValueToStringTransformer convert Boolean false to empty string

It's common in PHP for Boolean `false` to represent the lack of a value (e.g. core functions like `strpos()`) - therefore the code here should intuit this intention to represent the lack of something with `false` and convert it to an empty string the same way it does for `null`, rather than throwing a rather opaque exception.