ipython/ipython — pull request #2199 by Carreau (2012-07-25 14:27:34+00:00)
Title: Wrap JS published by %%javascript in try/catch

by default %%javascript will publish it's content in a try/catch and
display a warning in cell output if the expression raises.

This is should prevent some sneeky JS to prevent notebook to load.
and give more feedback to the user.

```
%%javascript
a.a=1
```
shows
```
ReferenceError: a is not defined
See your frontend Javascript console for more details.
```