[glib] GDBusWorker: if a read was cancelled it means we closed the connection

[Simon McVittie <smcv src gnome org>]

commit 5e0492da509aad12b93b732c449dae1a016367c1
Author: Simon McVittie <simon mcvittie collabora co uk>
Date:   Wed Oct 19 10:49:56 2011 +0100

    GDBusWorker: if a read was cancelled it means we closed the connection
    
    This was a regression caused by my previous work on GDBusWorker thread-safety
    (Bug #651268). The symptom is that if you disconnect a GDBusConnection
    locally, the default implementation of GDBusConnection::closed
    terminates your process, even though it shouldn't do that for
    locally-closed connections; this is because GDBusWorker didn't think a
    cancelled read was a local close.
    
    Bug: https://bugzilla.gnome.org/show_bug.cgi?id=662100
    Bug-NB: NB#287088
    Signed-off-by: Simon McVittie <simon mcvittie collabora co uk>
    Reviewed-by: David Zeuthen <davidz redhat com>

 gio/gdbusprivate.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)
---
diff --git a/gio/gdbusprivate.c b/gio/gdbusprivate.c
index c30a4ec..38b17f3 100644
--- a/gio/gdbusprivate.c
+++ b/gio/gdbusprivate.c
@@ -647,7 +647,17 @@ _g_dbus_worker_do_read_cb (GInputStream  *input_stream,
 
   if (bytes_read == -1)
     {
-      _g_dbus_worker_emit_disconnected (worker, TRUE, error);
+      /* Every async read that uses this callback uses worker->cancellable
+       * as its GCancellable. worker->cancellable gets cancelled if and only
+       * if the GDBusConnection tells us to close (either via
+       * _g_dbus_worker_stop, which is called on last-unref, or directly),
+       * so a cancelled read must mean our connection was closed locally.
+       */
+      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        _g_dbus_worker_emit_disconnected (worker, FALSE, NULL);
+      else
+        _g_dbus_worker_emit_disconnected (worker, TRUE, error);
+
       g_error_free (error);
       goto out;
     }