Mike Fleetwood authored Feb 28, 2021 and Curtis Gedak committed Mar 04, 2021

... in class Dialog_Partition_New and slightly refactor the code in
build_filesystems_combo() method which sets it.

Change the name from first_creatable_fs to default_fs to be more
immediately obvious what the variable represents.  As default_fs is used
to index the items in the combo_filesystem derived ComboBox, make it's
type an int to match the type of the parameter passed to
Gtk::ComboBox::set_active() [1].  Initialise default_fs to -1 (no
selection) in the class constructor [2], which also allows removal of
local variable set_first just used to track whether first_creatable_fs
had been assigned yet or not.

[1] gtkmm: Gtk::ComboBox Class Reference, set_active()
    https://developer.gnome.org/gtkmm/stable/classGtk_1_1ComboBox.html#a4f23cf08e85733d23f120935b235096d

[2] C++ FAQ / Should my constructors use "initialization lists" or
    "assignment"?
    https://isocpp.org/wiki/faq/ctors#init-lists