volunteer needed: event return values

[Owen Taylor <otaylor redhat com>]

The way event handlers are supposed to work is that
there return value is a boolean:

 TRUE -  the handler handled the event, no processing necessary
 FALSE - the handler didn't handle the event, continue processing

This applies both to the default handlers stored in the
class structure, and to connected signal handlers.

Unfortunately, a large fraction of GTK+'s event handlers are
broken and just always return FALSE.


Getting this right will be more even more important for GTK+-2.0
because we plan to change things so that a TRUE return not
only prevents propagation of the event to parent widgets, but
also stops the current signal emission, so other handlers
connected to the current widget.


So, the task is:

 Go through all the GTK+ widgets

  - Look for handlers for event signals.
  - Determine if they are correctly returning TRUE when
    handling events.
  - Make up a patch fixing cases which are definitely wrong.
  - Make a list of dubious cases that can be checked over
    by people who know the widgets in detail.

It's a reasonably big job - I'd guess it's probably 15-20 so 
hours of work, but quite important to get done.

If anybody is interested in doing this, (or doing this for
some subset of the GTK+ widgets), please follow up here.

Thanks,
                                        Owen