creation of folder fails due to missing permissions although permissions are sufficient

[Karl-Philipp Richter]

After entering a name for the new folder a dialog ~"creation of directory failed: permission denied" whereas the creation works fine in `nautilus` and on the command line with `mkdir`.

This is related to https://bugs.launchpad.net/ubuntu/+source/gtk+3.0/+bug/1435796, but not a duplicate.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: libgtk-3-0 3.14.13-0ubuntu1
Uname: Linux 4.1.4-040104-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Aug 6 11:09:18 2015
InstallationDate: Installed on 2015-06-08 (58 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gtk+3.0
UpgradeStatus: Upgraded to vivid on 2015-06-09 (57 days ago)

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https://wiki.ubuntu.com/Bugs/Upstream/GNOME. If you have done so, please tell us the number of the upstream bug (or the link), so we can add a bugwatch that will inform us about its status. Thanks in advance.