Add GBusNameWatcherFlags enumeration

This is mostly so it's easy to automatically launch services. E.g.

 $ ./example-watch-proxy -n com.redhat.virt.manager \
                         -o /com/redhat/virt/manager \
                         -i com.redhat.virt.manager \
                         -p -a
 +++ Acquired proxy object for remote object owned by :1.444
     bus:          Session Bus
     name:         com.redhat.virt.manager
     object path:  /com/redhat/virt/manager
     interface:    com.redhat.virt.manager
     properties:

will actually make the bus launch Virt Manager and wait for it to take
the name com.redhat.virt.manage before on_proxy_appeared() is called.

Also fix a bug where proxies weren't constructed if properties are
unwanted and the object has no properties.

13 files changed, 160 insertions, 21 deletions

diff --git a/gdbus/example-unix-fd-client.c b/gdbus/example-unix-fd-client.c
index 6729913..9e9678d 100644
--- a/gdbus/example-unix-fd-client.c
+++ b/gdbus/example-unix-fd-client.c
@@ -119,6 +119,7 @@ main (int argc, char *argv[])
 
   watcher_id = g_bus_watch_name (G_BUS_TYPE_SESSION,
                                  "org.gtk.GDBus.TestServer",
+                                 G_BUS_NAME_WATCHER_FLAGS_NONE,
                                  on_name_appeared,
                                  on_name_vanished,
                                  NULL,
diff --git a/gdbus/example-watch-name.c b/gdbus/example-watch-name.c
index 24e4df9..c907484 100644
--- a/gdbus/example-watch-name.c
+++ b/gdbus/example-watch-name.c
@@ -2,11 +2,13 @@
 
 static gchar *opt_name         = NULL;
 static gboolean opt_system_bus = FALSE;
+static gboolean opt_auto_start = FALSE;
 
 static GOptionEntry opt_entries[] =
 {
   { "name", 'n', 0, G_OPTION_ARG_STRING, &opt_name, "Name to watch", NULL },
   { "system-bus", 's', 0, G_OPTION_ARG_NONE, &opt_system_bus, "Use the system-bus instead of the session-bus", NULL },
+  { "auto-start", 'a', 0, G_OPTION_ARG_NONE, &opt_auto_start, "Instruct the bus to launch an owner for the name", NULL},
   { NULL}
 };
 
@@ -39,6 +41,7 @@ main (int argc, char *argv[])
   GMainLoop *loop;
   GOptionContext *opt_context;
   GError *error;
+  GBusNameWatcherFlags flags;
 
   g_type_init ();
 
@@ -60,8 +63,13 @@ main (int argc, char *argv[])
       goto out;
     }
 
+  flags = G_BUS_NAME_WATCHER_FLAGS_NONE;
+  if (opt_auto_start)
+    flags |= G_BUS_NAME_WATCHER_FLAGS_AUTO_START;
+
   watcher_id = g_bus_watch_name (opt_system_bus ? G_BUS_TYPE_SYSTEM : G_BUS_TYPE_SESSION,
                                  opt_name,
+                                 flags,
                                  on_name_appeared,
                                  on_name_vanished,
                                  NULL,
diff --git a/gdbus/example-watch-proxy.c b/gdbus/example-watch-proxy.c
index c768f58..8528e78 100644
--- a/gdbus/example-watch-proxy.c
+++ b/gdbus/example-watch-proxy.c
@@ -4,6 +4,8 @@ static gchar *opt_name         = NULL;
 static gchar *opt_object_path  = NULL;
 static gchar *opt_interface    = NULL;
 static gboolean opt_system_bus = FALSE;
+static gboolean opt_auto_start = FALSE;
+static gboolean opt_no_properties = FALSE;
 
 static GOptionEntry opt_entries[] =
 {
@@ -11,6 +13,8 @@ static GOptionEntry opt_entries[] =
   { "object-path", 'o', 0, G_OPTION_ARG_STRING, &opt_object_path, "Object path of the remote object", NULL },
   { "interface", 'i', 0, G_OPTION_ARG_STRING, &opt_interface, "D-Bus interface of remote object", NULL },
   { "system-bus", 's', 0, G_OPTION_ARG_NONE, &opt_system_bus, "Use the system-bus instead of the session-bus", NULL },
+  { "auto-start", 'a', 0, G_OPTION_ARG_NONE, &opt_auto_start, "Instruct the bus to launch an owner for the name", NULL},
+  { "no-properties", 'p', 0, G_OPTION_ARG_NONE, &opt_no_properties, "Do not load properties", NULL},
   { NULL}
 };
 
@@ -128,6 +132,8 @@ main (int argc, char *argv[])
   GMainLoop *loop;
   GOptionContext *opt_context;
   GError *error;
+  GBusNameWatcherFlags flags;
+  GDBusProxyFlags proxy_flags;
 
   g_type_init ();
 
@@ -151,12 +157,21 @@ main (int argc, char *argv[])
       goto out;
     }
 
+  flags = G_BUS_NAME_WATCHER_FLAGS_NONE;
+  if (opt_auto_start)
+    flags |= G_BUS_NAME_WATCHER_FLAGS_AUTO_START;
+
+  proxy_flags = G_DBUS_PROXY_FLAGS_NONE;
+  if (opt_no_properties)
+    proxy_flags |= G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES;
+
   watcher_id = g_bus_watch_proxy (opt_system_bus ? G_BUS_TYPE_SYSTEM : G_BUS_TYPE_SESSION,
                                   opt_name,
+                                  flags,
                                   opt_object_path,
                                   opt_interface,
                                   G_TYPE_DBUS_PROXY,
-                                  G_DBUS_PROXY_FLAGS_NONE,
+                                  proxy_flags,
                                   on_proxy_appeared,
                                   on_proxy_vanished,
                                   NULL,
diff --git a/gdbus/gdbusenums.h b/gdbus/gdbusenums.h
index 64a080e..c40d658 100644
--- a/gdbus/gdbusenums.h
+++ b/gdbus/gdbusenums.h
@@ -61,12 +61,11 @@ typedef enum
 /**
  * GBusNameOwnerFlags:
  * @G_BUS_NAME_OWNER_FLAGS_NONE: No flags set.
- * @G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT: Allow another message connection to take the name.
- * @G_BUS_NAME_OWNER_FLAGS_REPLACE: If another message bus connection
- * owns the name and have specified #G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT, then
- * take the name from the other connection.
+ * @G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT: Allow another message bus connection to claim the the name.
+ * @G_BUS_NAME_OWNER_FLAGS_REPLACE: If another message bus connection owns the name and have
+ * specified #G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT, then take the name from the other connection.
  *
- * Flags used when constructing a #GBusNameOwner.
+ * Flags used in g_bus_own_name().
  */
 typedef enum
 {
@@ -76,6 +75,21 @@ typedef enum
 } GBusNameOwnerFlags;
 
 /**
+ * GBusNameWatcherFlags:
+ * @G_BUS_NAME_WATCHER_FLAGS_NONE: No flags set.
+ * @G_BUS_NAME_WATCHER_FLAGS_AUTO_START: If no-one owns the name when
+ * beginning to watch the name, ask the bus to launch an owner for the
+ * name.
+ *
+ * Flags used in g_bus_watch_name().
+ */
+typedef enum
+{
+  G_BUS_NAME_WATCHER_FLAGS_NONE = 0,
+  G_BUS_NAME_WATCHER_FLAGS_AUTO_START = (1<<0)
+} GBusNameWatcherFlags;
+
+/**
  * GDBusProxyFlags:
  * @G_DBUS_PROXY_FLAGS_NONE: No flags set.
  * @G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES: Don't load properties.
diff --git a/gdbus/gdbusnamewatching.c b/gdbus/gdbusnamewatching.c
index ef030f2..fe6cc41 100644
--- a/gdbus/gdbusnamewatching.c
+++ b/gdbus/gdbusnamewatching.c
@@ -58,6 +58,7 @@ typedef struct
   volatile gint             ref_count;
   guint                     id;
   gchar                    *name;
+  GBusNameWatcherFlags      flags;
   gchar                    *name_owner;
   GBusNameAppearedCallback  name_appeared_handler;
   GBusNameVanishedCallback  name_vanished_handler;
@@ -356,6 +357,77 @@ get_name_owner_cb (GObject      *source_object,
 /* ---------------------------------------------------------------------------------------------------- */
 
 static void
+invoke_get_name_owner (Client *client)
+{
+  g_dbus_connection_invoke_method (client->connection,
+                                   "org.freedesktop.DBus",  /* bus name */
+                                   "/org/freedesktop/DBus", /* object path */
+                                   "org.freedesktop.DBus",  /* interface name */
+                                   "GetNameOwner",          /* method name */
+                                   g_variant_new ("(s)", client->name),
+                                   G_DBUS_INVOKE_METHOD_FLAGS_NONE,
+                                   -1,
+                                   NULL,
+                                   (GAsyncReadyCallback) get_name_owner_cb,
+                                   client_ref (client));
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static void
+start_service_by_name_cb (GObject      *source_object,
+                          GAsyncResult *res,
+                          gpointer      user_data)
+{
+  Client *client = user_data;
+  GVariant *result;
+
+  result = NULL;
+
+  result = g_dbus_connection_invoke_method_finish (client->connection,
+                                                   res,
+                                                   NULL);
+  if (result != NULL)
+    {
+      guint32 start_service_result;
+      g_variant_get (result, "(u)", &start_service_result);
+
+      if (start_service_result == 1) /* DBUS_START_REPLY_SUCCESS */
+        {
+          invoke_get_name_owner (client);
+        }
+      else if (start_service_result == 2) /* DBUS_START_REPLY_ALREADY_RUNNING */
+        {
+          invoke_get_name_owner (client);
+        }
+      else
+        {
+          g_warning ("Unexpected reply %d from StartServiceByName() method", start_service_result);
+          call_vanished_handler (client, FALSE);
+          client->initialized = TRUE;
+        }
+    }
+  else
+    {
+      /* Errors are not unexpected; the bus will reply e.g.
+       *
+       *   org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.Epiphany2
+       *   was not provided by any .service files
+       *
+       * so just report vanished.
+       */
+      call_vanished_handler (client, FALSE);
+      client->initialized = TRUE;
+    }
+
+  if (result != NULL)
+    g_variant_unref (result);
+  client_unref (client);
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static void
 has_connection (Client *client)
 {
   /* listen for disconnection */
@@ -375,18 +447,25 @@ has_connection (Client *client)
                                                                                    client,
                                                                                    NULL);
 
-  /* check owner */
-  g_dbus_connection_invoke_method (client->connection,
-                                   "org.freedesktop.DBus",  /* bus name */
-                                   "/org/freedesktop/DBus", /* object path */
-                                   "org.freedesktop.DBus",  /* interface name */
-                                   "GetNameOwner",          /* method name */
-                                   g_variant_new ("(s)", client->name),
-                                   G_DBUS_INVOKE_METHOD_FLAGS_NONE,
-                                   -1,
-                                   NULL,
-                                   (GAsyncReadyCallback) get_name_owner_cb,
-                                   client_ref (client));
+  if (client->flags & G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
+    {
+      g_dbus_connection_invoke_method (client->connection,
+                                       "org.freedesktop.DBus",  /* bus name */
+                                       "/org/freedesktop/DBus", /* object path */
+                                       "org.freedesktop.DBus",  /* interface name */
+                                       "StartServiceByName",    /* method name */
+                                       g_variant_new ("(su)", client->name, 0),
+                                       G_DBUS_INVOKE_METHOD_FLAGS_NONE,
+                                       -1,
+                                       NULL,
+                                       (GAsyncReadyCallback) start_service_by_name_cb,
+                                       client_ref (client));
+    }
+  else
+    {
+      /* check owner */
+      invoke_get_name_owner (client);
+    }
 }
 
 
@@ -416,6 +495,7 @@ connection_get_cb (GObject      *source_object,
  * g_bus_watch_name:
  * @bus_type: The type of bus to watch a name on (can't be #G_BUS_TYPE_NONE).
  * @name: The name (well-known or unique) to watch.
+ * @flags: Flags from the #GBusNameWatcherFlags enumeration.
  * @name_appeared_handler: Handler to invoke when @name is known to exist.
  * @name_vanished_handler: Handler to invoke when @name is known to not exist.
  * @user_data: User data to pass to handlers.
@@ -457,6 +537,7 @@ connection_get_cb (GObject      *source_object,
 guint
 g_bus_watch_name (GBusType                  bus_type,
                   const gchar              *name,
+                  GBusNameWatcherFlags      flags,
                   GBusNameAppearedCallback  name_appeared_handler,
                   GBusNameVanishedCallback  name_vanished_handler,
                   gpointer                  user_data,
@@ -475,6 +556,7 @@ g_bus_watch_name (GBusType                  bus_type,
   client->ref_count = 1;
   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
   client->name = g_strdup (name);
+  client->flags = flags;
   client->name_appeared_handler = name_appeared_handler;
   client->name_vanished_handler = name_vanished_handler;
   client->user_data = user_data;
diff --git a/gdbus/gdbusnamewatching.h b/gdbus/gdbusnamewatching.h
index 1f74e26..2692c66 100644
--- a/gdbus/gdbusnamewatching.h
+++ b/gdbus/gdbusnamewatching.h
@@ -60,6 +60,7 @@ typedef void (*GBusNameVanishedCallback) (GDBusConnection *connection,
 
 guint g_bus_watch_name   (GBusType                  bus_type,
                           const gchar              *name,
+                          GBusNameWatcherFlags      flags,
                           GBusNameAppearedCallback  name_appeared_handler,
                           GBusNameVanishedCallback  name_vanished_handler,
                           gpointer                  user_data,
diff --git a/gdbus/gdbusproxy.c b/gdbus/gdbusproxy.c
index cbdd5e4..e248e99 100644
--- a/gdbus/gdbusproxy.c
+++ b/gdbus/gdbusproxy.c
@@ -839,9 +839,17 @@ async_initable_init_finish (GAsyncInitable  *initable,
 
   result = g_simple_async_result_get_op_res_gpointer (simple);
   if (result == NULL)
-    goto out;
-
-  process_get_all_reply (proxy, result);
+    {
+      if (!(proxy->priv->flags & G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES))
+        {
+          g_simple_async_result_propagate_error (simple, error);
+          goto out;
+        }
+    }
+  else
+    {
+      process_get_all_reply (proxy, result);
+    }
 
   subscribe_to_signals (proxy);
 
diff --git a/gdbus/gdbusproxywatching.c b/gdbus/gdbusproxywatching.c
index 24390ff..185b347 100644
--- a/gdbus/gdbusproxywatching.c
+++ b/gdbus/gdbusproxywatching.c
@@ -263,6 +263,7 @@ on_name_vanished (GDBusConnection *connection,
  * g_bus_watch_proxy:
  * @bus_type: The type of bus to watch a name on (can't be #G_BUS_TYPE_NONE).
  * @name: The name (well-known or unique) to watch.
+ * @flags: Flags from the #GBusNameWatcherFlags enumeration.
  * @object_path: The object path of the remote object to watch.
  * @interface_name: The D-Bus interface name for the proxy.
  * @interface_type: The #GType for the kind of proxy to create. This must be a #GDBusProxy derived type.
@@ -309,6 +310,7 @@ on_name_vanished (GDBusConnection *connection,
 guint
 g_bus_watch_proxy (GBusType                   bus_type,
                    const gchar               *name,
+                   GBusNameWatcherFlags       flags,
                    const gchar               *object_path,
                    const gchar               *interface_name,
                    GType                      interface_type,
@@ -342,6 +344,7 @@ g_bus_watch_proxy (GBusType                   bus_type,
     g_main_context_ref (client->main_context);
   client->name_watcher_id = g_bus_watch_name (bus_type,
                                               name,
+                                              flags,
                                               on_name_appeared,
                                               on_name_vanished,
                                               client,
diff --git a/gdbus/gdbusproxywatching.h b/gdbus/gdbusproxywatching.h
index 2349af9..b63e09f 100644
--- a/gdbus/gdbusproxywatching.h
+++ b/gdbus/gdbusproxywatching.h
@@ -65,6 +65,7 @@ typedef void (*GBusProxyVanishedCallback) (GDBusConnection *connection,
 
 guint g_bus_watch_proxy   (GBusType                   bus_type,
                            const gchar               *name,
+                           GBusNameWatcherFlags       flags,
                            const gchar               *object_path,
                            const gchar               *interface_name,
                            GType                      interface_type,
diff --git a/gdbus/tests/introspection.c b/gdbus/tests/introspection.c
index cde1eab..19b500f 100644
--- a/gdbus/tests/introspection.c
+++ b/gdbus/tests/introspection.c
@@ -116,6 +116,7 @@ test_introspection_parser (void)
 
   watcher_id = g_bus_watch_proxy (G_BUS_TYPE_SESSION,
                                   "com.example.TestService",
+                                  G_BUS_NAME_WATCHER_FLAGS_NONE,
                                   "/com/example/TestObject",
                                   "com.example.Frob",
                                   G_TYPE_DBUS_PROXY,
diff --git a/gdbus/tests/names.c b/gdbus/tests/names.c
index b66200f..161dc1a 100644
--- a/gdbus/tests/names.c
+++ b/gdbus/tests/names.c
@@ -548,6 +548,7 @@ test_bus_watch_name (void)
   data.expect_null_connection = TRUE;
   id = g_bus_watch_name (G_BUS_TYPE_SESSION,
                          "org.gtk.GDBus.Name1",
+                         G_BUS_NAME_WATCHER_FLAGS_NONE,
                          name_appeared_handler,
                          name_vanished_handler,
                          &data,
@@ -587,6 +588,7 @@ test_bus_watch_name (void)
   data.num_vanished = 0;
   id = g_bus_watch_name (G_BUS_TYPE_SESSION,
                          "org.gtk.GDBus.Name1",
+                         G_BUS_NAME_WATCHER_FLAGS_NONE,
                          name_appeared_handler,
                          name_vanished_handler,
                          &data,
@@ -619,6 +621,7 @@ test_bus_watch_name (void)
   data.num_free_func = 0;
   id = g_bus_watch_name (G_BUS_TYPE_SESSION,
                          "org.gtk.GDBus.Name1",
+                         G_BUS_NAME_WATCHER_FLAGS_NONE,
                          name_appeared_handler,
                          name_vanished_handler,
                          &data,
diff --git a/gdbus/tests/proxy.c b/gdbus/tests/proxy.c
index 13647d0..5172276 100644
--- a/gdbus/tests/proxy.c
+++ b/gdbus/tests/proxy.c
@@ -450,6 +450,7 @@ test_proxy (void)
 
   watcher_id = g_bus_watch_proxy (G_BUS_TYPE_SESSION,
                                   "com.example.TestService",
+                                  G_BUS_NAME_WATCHER_FLAGS_NONE,
                                   "/com/example/TestObject",
                                   "com.example.Frob",
                                   G_TYPE_DBUS_PROXY,
diff --git a/gdbus/tests/threading.c b/gdbus/tests/threading.c
index 00e7ca7..f575ab8 100644
--- a/gdbus/tests/threading.c
+++ b/gdbus/tests/threading.c
@@ -462,6 +462,7 @@ test_method_calls_in_thread (void)
 
   watcher_id = g_bus_watch_proxy (G_BUS_TYPE_SESSION,
                                   "com.example.TestService",
+                                  G_BUS_NAME_WATCHER_FLAGS_NONE,
                                   "/com/example/TestObject",
                                   "com.example.Frob",
                                   G_TYPE_DBUS_PROXY,