knockout/knockout — pull request #1530 by AdeeLNX (2014-09-10 08:22:02+00:00)
Title: Cssbinding issue 1468

Css binding not refresh the UI when its value is set to null because css code checks for

```JavaScript
typeof value == "object"
```
which will match null.

The fix is:
```JavaScript
value !== null && typeof value == "object"
```

This is from https://github.com/knockout/knockout/issues/1468 issue.