Description of problem:
Selecting more than one cell freezes Calc. This makes it almost unusable.

Version-Release number of selected component (if applicable):
$ rpm -qa | grep -e libreoffice-gtk -e libreoffice-calc -e ^gtk[23] | sort
gtk2-2.24.31-1.fc24.i686
gtk2-2.24.31-1.fc24.x86_64
gtk2-engines-2.20.2-11.fc24.x86_64
gtk3-3.20.9-1.fc24.x86_64
libreoffice-calc-5.1.5.2-6.fc24.x86_64
libreoffice-gtk2-5.1.5.2-6.fc24.x86_64
libreoffice-gtk3-5.1.5.2-6.fc24.x86_64

How reproducible:
Almost always

Steps to Reproduce:
1. Open Calc
2. Select multiple cells

Actual results:
Calc freezes. It's kind of still alive as I can close it and, if I have unsaved changes, there will be a dialog to save my changes (sometimes it's black and unusable though). Sometimes I can escape the freeze by clicking multiple times fast in the selection, but it's seldom.

Expected results:
Calc doesn't freeze and I can do something with the selection.

Additional info:

The issue seems related to Bug 1373933 but I'm using F24 and shouldn't be impacted by the referenced commit (unless it's been backported). Further I can't reproduce it using Draw and selecting objects.

Anyway, if I call 'SAL_USE_VCLPLUGIN=gtk libreoffice --calc' the problem is gone, so it seems also like a gtk3-specific issue.

The problem did already exist a while ago but I'm pretty sure that it went away already before the summer and has come back somewhere in-between (but I don't use Calc regularly at home).

I don't think it's relevant but I'm using KDE (latest version F24).