Symbols, added in gtk+ between our merging with 2.5.x and 2.6.0
They need to be added to the defs file, probably manually.

gtk_list_store_insert_with_values
gtk_list_store_insert_with_valuesv
gtk_text_layout_get_iter_at_position (NOT MERGED INTERNAL API)
gtk_dialog_set_alternative_button_order_from_array


Symbols, encountered while updating reference docs during the 2.24
development cycle:

class GtkAccelGroup:
    def GtkAccelGroup.activate(accel_quark, acceleratable, accel_key, accel_mods)
    def GtkAccelGroup.find((*find_func)
    def GtkAccelGroup.query(accel_key, accel_mods, n_entries)

class GtkBuildable:
    def GtkBuildable.set_buildable_property(builder, name, value)
    def GtkBuildable.custom_tag_start(builder, child, tagname, parser, data)
    def GtkBuildable.custom_tag_end(builder, child, tagname, data)
    def GtkBuildable.custom_finished(builder, child, tagname, data)

class GtkCalendar:
    def GtkCalendar.set_detail_func(func, data, destroy)

class GtkClipboard:
    def GtkClipboard.wait_for_uris()
    def GtkClipboard.request_uris(callback, user_data)

class GtkEntryBuffer:
    def GtkEntryBuffer(initial_chars, n_initial_chars)
    def GtkEntryBuffer.set_text(chars, n_chars)
    def GtkEntryBuffer.insert_text(position, chars, n_chars)
    def GtkEntryBuffer.delete_text(position, n_chars)
    def GtkEntryBuffer.emit_inserted_text(position, chars, n_chars)
    def GtkEntryBuffer.emit_deleted_text(position, n_chars)

class GtkFileChooser:
    def GtkFileChooser.set_create_folders(create_folders)
    def GtkFileChooser.get_create_folders()

class GtkPrintContext:
    def GtkPrintContext.get_hard_margins(top, bottom, left, right)

class GtkRange:
    def GtkRange.get_slider_range(slider_start, slider_end)

class GtkSelectionData:
    def GtkSelectionData.get_data()
    def GtkSelectionData.get_selection()

class GtkSettings:
    def GtkSettings.set_property_value(name, svalue)

class GtkStyle:
    def GtkStyle.paint_spinner(style, window, state_type, area, widget, detail, step, x, y, width, height)
    def GtkStyle.get_style_property(widget_type, property_name, value)
    def GtkStyle.get_valist(widget_type, first_property_name, var_args)
    def GtkStyle.get(widget_type, first_property_name)

class GtkTreeSelection:
    def GtkTreeSelection.get_select_function()

class GtkWindowGroup:
    def GtkWindowGroup.list_windows()
    def GtkWindowGroup.get_current_grab() -> undocumented in GTK+