Description of problem:
I was cleaning my rpm config files:

sudo rpmconf -a -fdiffuse

It happened when I tried to merge cups-browsed.conf files.

Version-Release number of selected component:
diffuse-0.4.8-1.fc20

Additional info:
reporter:       libreport-2.2.3
cmdline:        /usr/bin/python2 /bin/diffuse /etc/cups/cups-browsed.conf /etc/cups/cups-browsed.conf.rpmnew
executable:     /bin/diffuse
kernel:         3.19.8-100.fc20.x86_64
runlevel:       N 5
type:           Python
uid:            0

Truncated backtrace:
diffuse:7392:__init__:AttributeError: 'NoneType' object has no attribute 'get_width'

Traceback (most recent call last):
  File "/bin/diffuse", line 8329, in <module>
    diff = Diffuse(rc_dir)
  File "/bin/diffuse", line 7392, in __init__
    w, h = p0.get_width(), p0.get_height()
AttributeError: 'NoneType' object has no attribute 'get_width'

Local variables in innermost frame:
DIFFUSE_STOCK_RIGHT_LEFT: 'diffuse-right-left'
rc_dir: '/root/.config/diffuse'
self: <Diffuse object at 0x1d78280 (GtkWindow at 0x1f9a0d0)>
p0: None
factory: <gtk.IconFactory object at 0x202e140 (GtkIconFactory at 0x1c62580)>
DIFFUSE_STOCK_LEFT_RIGHT: 'diffuse-left-right'
vbox: <gtk.VBox object at 0x202e0f0 (GtkVBox at 0x1ab16f0)>
DIFFUSE_STOCK_NEW_3WAY_MERGE: 'diffuse-new-3way-merge'
DIFFUSE_STOCK_NEW_2WAY_MERGE: 'diffuse-new-2way-merge'
accel_group: <gtk.AccelGroup object at 0x1d782d0 (GtkAccelGroup at 0x1bc9500)>