[7.0/trunk] pyeval.js wrap_context should check for undefined variables

[Andrius Preimantas @ hbee]

web revno: 4011
server revno: 5047
addons revno: 9358

This one is very technical so I'll let the attached video explain what is wrong.

The button seen in the video is the one I've implemented to open product of the order line. Here's the button declaration:
<button name="open_product_id" type="object" string="Open Product" icon="gtk-open" context="{'product_id': product_id}"/>

As you can see, I try to set context value, which (I think) invokes the method wrap_context. If I remove the context in the button declaration, everything works fine.