GNOME Printer Setup Tool: Printers are discovered only through a hard-coded list of CUPS backends

[Till Kamppeter]

For development of printing infrastructure I use a test CUPS backend (attached, to be installed in /usr/lib/cups/backend/ and to be made executable) reporting printers as detected which in reality do not exist, so that I do not need the actual printer models for the test. Other users use manufacturer-supplied printer drivers which bring their own CUPS backends, and Ubuntu also ships the "hpfax" backend which is not in the hard-coded list.

The source code of gnome-control-center, file panels/printers/pp-utils.c contains

----------
[...]
static void
get_device_attributes_async_scb (GHashTable *result,
                                 gpointer user_data)
{
  [...]
  const gchar *backends[] =
    {"hpfax", "ncp", "beh", "bluetooth", "snmp",
     "dnssd", "hp", "ipp", "lpd", "parallel",
     "serial", "socket", "usb", NULL};
  [...]
----------

and tests show that the tool is actually only discovering printers through these backends. It is easy to make CUPS using all backends for detecting printers, one can do it by a single function call. Other printer setup tools do it this way and I expect gnome-control-center to also use all CUPS backends, so that users who use special backends can set up their printers.

[Till Kamppeter (till-kamppeter)]

This is a regression compared to Quantal. There system-config-printer was used which did it correctly.

[Sebastien Bacher (seb128)]

(changing the milestone since we are past feature freeze, setting to beta2)