A regression was introduced, according to acrmp, at commit 4eba6949adc5dbabe5b054d42ecebb3fdeffc987 (version 0.10.10 of chef).
The symptoms are that the following code would return 'nil' instead the correct value. For example:
Instead of the values of '0' or '420' being returned as expected, you will get a value of 'nil'.
This was found when writing tests using minitest-chef-handler against Chef 0.10.10 and 0.10.12. This is a regression post 0.10.8 (where the expected return values are correct).