Just code cleanup: This is much less error-prone than manual nesting,
and will mesh very well with future changes to use the libgsystem
cleanup macros.
GObject creation cannot normally fail, except for types that implement
GInitable and take a GError in their _new() method. Some NM types
override constructor() and return NULL in some cases, but these
generally only happen in the case of programmer error (eg, failing to
set a mandatory property), and so crashing is reasonable (and most
likely inevitable anyway).
So, remove all NULL checks after calls to g_object_new() and its
myriad wrappers.
https://bugzilla.gnome.org/show_bug.cgi?id=693678
When updating connections, it is less confusing to reuse the existing file
instead of renaming files according to connection's ID. That reduces surprises
of moving connection files when a connection is edited.
When a connection changes on-disk, the in-memory copy of it may contain
transient secrets (agent-owned or not saved) that dont' get written out
to disk. When comparing the on-disk copy to the in-memory copy make sure
transient secrets are ignored so that we don't re-read the on-disk copy
needlessly.
