WCT's owned by the callee

[Tommi Höynälänmaa]

Hi

Some of the Pango functions, such as pango_attr_list_insert, take the 
ownership of the argument attribute pointer. Consequently these 
arguments should be declared callee-owned. I had to modify the g-wrap 
source code in order to allow WCT arguments to be declared callee-owned. 
The present wrapper procedures cause segmentation violations when Pango 
attributes are used. Do you agree that these changes should be made into 
the guile-gnome library?

     - Tommi Höynälänmaa