[NUI] add null checking for equality operator of ControlState (#2079)
authorYeongJong Lee <cleanlyj@naver.com>
Thu, 29 Oct 2020 05:47:21 +0000 (14:47 +0900)
committerGitHub <noreply@github.com>
Thu, 29 Oct 2020 05:47:21 +0000 (14:47 +0900)
commit2cfd515185cb524a086403d33cd0904d6022c4a4
tree2ac87ce5ce25a8ea4918333dd8f85bb490ac278a
parentcac4004390875dce25f3088a0265f14b95101c41
[NUI] add null checking for equality operator of ControlState (#2079)

This is patch to prevent a null reference exception in the following
code.

```cs
bool b = null == ControlState.Pressed;
```

Co-authored-by: Jiyun Yang <ji.yang@samsung.com>
src/Tizen.NUI/src/public/BaseComponents/ControlState.cs