fd.o #23651: use preferred handler in two cases

- from requests that caused a channel to be created
- when a request approves a pending dispatch operation

3 files changed, 54 insertions, 1 deletions

diff --git a/src/mcd-dispatch-operation.c b/src/mcd-dispatch-operation.c
index c6bfe47b..b55b7d39 100644
--- a/src/mcd-dispatch-operation.c
+++ b/src/mcd-dispatch-operation.c
@@ -382,17 +382,38 @@ mcd_dispatch_operation_set_property (GObject *obj, guint prop_id,
         break;
 
     case PROP_CHANNELS:
+        /* because this is construct-only, we can assert that: */
         g_assert (priv->channels == NULL);
+        g_assert (priv->handler == NULL);
+
         priv->channels = g_value_get_pointer (val);
         if (G_LIKELY (priv->channels))
         {
             /* get the connection from the first channel */
             McdChannel *channel = MCD_CHANNEL (priv->channels->data);
+            const gchar *preferred_handler;
             priv->connection = (McdConnection *)
                 mcd_mission_get_parent (MCD_MISSION (channel));
             if (G_LIKELY (priv->connection))
                 g_object_ref (priv->connection);
 
+            /* if the first channel is actually a channel request, get the
+             * preferred handler from it */
+            preferred_handler =
+              _mcd_channel_get_request_preferred_handler (channel);
+
+            if (preferred_handler != NULL &&
+                g_str_has_prefix (preferred_handler, MCD_CLIENT_BASE_NAME) &&
+                tp_dbus_check_valid_bus_name (preferred_handler,
+                                              TP_DBUS_NAME_TYPE_WELL_KNOWN,
+                                              NULL))
+            {
+                DEBUG ("Extracted preferred handler: %s",
+                       preferred_handler);
+                priv->handler = g_strdup (preferred_handler +
+                                          MCD_CLIENT_BASE_NAME_LEN);
+            }
+
             /* reference the channels */
             for (list = priv->channels; list != NULL; list = list->next)
                 g_object_ref (list->data);
@@ -826,3 +847,26 @@ _mcd_dispatch_operation_unblock_finished (McdDispatchOperation *self)
         }
     }
 }
+
+gboolean
+mcd_dispatch_operation_check_handler (const gchar *handler)
+{
+    /* NULL-safety: treat both NULL and "" as "unspecified" */
+    if (handler == NULL)
+      return FALSE;
+
+    DEBUG ("handler: '%s'", handler);
+
+    if (!g_str_has_prefix (handler, MCD_CLIENT_BASE_NAME) ||
+        !tp_dbus_check_valid_bus_name (handler,
+                                       TP_DBUS_NAME_TYPE_WELL_KNOWN, NULL))
+    {
+        DEBUG ("handler name '%s' is bad", handler);
+        return FALSE;
+    }
+
+    if (*handler != '\0')
+      return TRUE;
+
+    return FALSE;
+}
diff --git a/src/mcd-dispatch-operation.h b/src/mcd-dispatch-operation.h
index 918afa5e..2c4fe746 100644
--- a/src/mcd-dispatch-operation.h
+++ b/src/mcd-dispatch-operation.h
@@ -67,5 +67,7 @@ void mcd_dispatch_operation_handle_with (McdDispatchOperation *operation,
                                          const gchar *handler_path,
                                          GError **error);
 
+gboolean mcd_dispatch_operation_check_handler (const gchar *handler);
+
 G_END_DECLS
 #endif
diff --git a/src/mcd-dispatcher.c b/src/mcd-dispatcher.c
index 8ed59196..b6132ada 100644
--- a/src/mcd-dispatcher.c
+++ b/src/mcd-dispatcher.c
@@ -3705,6 +3705,12 @@ _mcd_dispatcher_add_channel_request (McdDispatcher *dispatcher,
     }
     else
     {
+        const gchar *preferred_handler =
+            _mcd_channel_get_request_preferred_handler (request);
+
+        if (!mcd_dispatch_operation_check_handler (preferred_handler))
+            preferred_handler = NULL;
+
         _mcd_channel_set_request_proxy (request, channel);
         if (status == MCD_CHANNEL_STATUS_DISPATCHING)
         {
@@ -3719,7 +3725,8 @@ _mcd_dispatcher_add_channel_request (McdDispatcher *dispatcher,
                  * terminate */
                 if (G_LIKELY (context->operation))
                     mcd_dispatch_operation_handle_with (context->operation,
-                                                        NULL, NULL);
+                                                        preferred_handler,
+                                                        NULL);
             }
             else
                 context->skip_approval = TRUE;