Calc not able to correctly set a serie

[dino99]

Using Calc with a gnome-shell session

into a column, i want to get a two selected cells to fill some other cells. But 'r1c5' is not understood as a unique value, and give a wrong result:

expected:
r1c5
r1c5
r1c5
r1c5
r1c5
r1c5
r1c5
r1c5
r1c5
r1c5

what is got instead:
r1c5
r1c5
r1c6
r1c6
r1c7
r1c7
r1c8
r1c8
r1c9
r1c9

howto: select the two first cells, then with the mouse, expand to the other cells.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: libreoffice-calc 1:5.1.3-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-27.46-generic 4.4.13
Uname: Linux 4.4.0-27-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: GNOME
Date: Sat Jun 25 09:26:56 2016
SourcePackage: libreoffice
UpgradeStatus: No upgrade log present (probably fresh install)