Creating UEFI machine throws exception in virt-manager

[Honza]

1. Install UEFI: apt-get install ovmf
2. Create machine in virt-manager, check customize configuration before install
3. Click overview, for "firmware" choose "uefi", click apply
Following exception has occured:

'NoneType' object has no attribute 'rfind'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/details.py", line 1887, in config_apply
    ret = self.config_overview_apply()
  File "/usr/share/virt-manager/virtManager/details.py", line 1979, in config_overview_apply
    self.vm.rename_domain(self.widget("overview-name").get_text())
  File "/usr/share/virt-manager/virtManager/domain.py", line 596, in rename_domain
    new_nvram, old_nvram = self._copy_nvram_file(new_name)
  File "/usr/share/virt-manager/virtManager/domain.py", line 571, in _copy_nvram_file
    nvram_dir = os.path.dirname(old_nvram.path)
  File "/usr/lib/python2.7/posixpath.py", line 122, in dirname
    i = p.rfind('/') + 1
AttributeError: 'NoneType' object has no attribute 'rfind'

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: virt-manager 1:1.5.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.18.0-13.14-generic 4.18.17
Uname: Linux 4.18.0-13-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sat Feb 16 00:38:24 2019
InstallationDate: Installed on 2018-09-22 (146 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=cs_CZ.UTF-8
 SHELL=/bin/bash
SourcePackage: virt-manager
UpgradeStatus: Upgraded to bionic on 2019-01-16 (30 days ago)

[Honza (honza889)]

Same bug in RHEL: https://bugzilla.redhat.com/show_bug.cgi?id=1667308