When doing size-requests and get_natural_size() calls, use 0 as
the base value instead of -1, because size_request code assumes
that widget->requesition is initialized at 0.
Because "size-request" signal can be handled by signal connections as well
as by third party derived classes it is necessary to always fire the
"size-request" signal for every recalculation of the widget requisition,
now gtksizegroup.c:do_size_request() fires the signal first and allows it
to overflow the minimum/natural sizes returned by extended layout
implementations.
GtkWidget->get_natural_size() is now left assigning default -1 values to
ensure they both get overridden by the size-request handling.
Getting the desired size of a GtkWidget must always be done with
gtk_widget_get_desired_size() and never with
gtk_extended_layout_get_desired_size() directly as the former passes
through size group logic and updates the widget->requisition cache.
Removed the size_request() handling on the class and calculate
minimum size from get_desired_size(); base the natural width on
either the minimum of column headers, or a greater natural request
of the columns renderers.
Applied patch to add height-for-width/width-for-height suppot
to GtkScrolledWindow plus modifications to use gtk_widget_get_desired_size()
to query children sized instead of directly calling the layout api, plus
removed the ->size_request() implementation interfering with the mess.
We should not unref the model here, it might not even exist anymore.
Instead check if it exists and only use it if it does.
The unref was leftover from a previous fix in
ba9f53397f.
Spotted by Matthias Clasen in
https://bugzilla.gnome.org/show_bug.cgi?id=614099
In certain cases the menu label of a notebook page will be reused after the
page was removed from the notebook, for instance when a page is dragged from
one notebook to another. For such cases make sure that the menu label isn't
destroyed as part of destroying the menu item it was in.
