Sometimes, the calling interface is blank when make an emergency call without sim card

[liufeng]

system-image-cli -i
current build number: 80
device name: arale
channel: ubuntu-touch/devel-proposed/meizu.en
last update: 2015-10-05 08:10:27
version version: 80
version ubuntu: 20150802
version device: 20150709-8965e37
version custom: 20150716-819-8-42

step by step
1.No sim card insert
2.Open dialer APP
3.Enter emergency call ,such as 110. tap dialer button.
Expected result:
It is not possible to make emergency call with no SIM
Actual result:
It is not possible to make emergency call with no SIM. but the calling interface is blank.