mmp/pbrt-v2 — pull request #12 by GraphicsMe (2013-04-26 12:13:52+00:00)
Title: 0 is incorrectly considered a power of 2 in function IsPowerOf2

In file /src/core/pbrt.h, fuction IsPowerOf2, 0 is considered a power of 2.
The remedy is straight forward. Please check it out.