Merge pull request #7673 from pengli:deriv
authorAlexander Alekhin <alexander.a.alekhin@gmail.com>
Thu, 17 Nov 2016 09:40:27 +0000 (09:40 +0000)
committerAlexander Alekhin <alexander.a.alekhin@gmail.com>
Thu, 17 Nov 2016 09:40:27 +0000 (09:40 +0000)

Trivial merge