[gdm/benzea/fix-conversation-error-reporting] session: Initialize DBus error domain before resolving errors

[Benjamin Berg <bberg src gnome org>]

commit c9ac5be7cd6577affcc85f6fb32f677388003e6a
Author: Benjamin Berg <bberg redhat com>
Date:   Wed Mar 10 11:43:00 2021 +0100

    session: Initialize DBus error domain before resolving errors
    
    We would not initialize the DBus error domain before we retrieved the
    first error, but only did so to compare the error after receiving them.
    This means that the first error we received will not be resolved
    correctly, while all subsequent ones are resolved.
    
    Fix this by calling GDM_SESSION_WORKER_ERROR from gdm_session_class_init
    and add gdm_dbus_error_ensure to make sure this can never be optimized
    away.

 daemon/gdm-dbus-util.c | 14 ++++++++++++++
 daemon/gdm-dbus-util.h |  2 ++
 daemon/gdm-session.c   |  3 +++
 3 files changed, 19 insertions(+)
---
diff --git a/daemon/gdm-dbus-util.c b/daemon/gdm-dbus-util.c
index b71da7fd8..844d60abf 100644
--- a/daemon/gdm-dbus-util.c
+++ b/daemon/gdm-dbus-util.c
@@ -183,3 +183,17 @@ gdm_dbus_get_uid_for_name (const char  *system_bus_name,
 
         return retval;
 }
+
+void
+gdm_dbus_error_ensure (GQuark domain)
+{
+        /* The primary purpose of this function is to make sure the error quark
+         * is registered internally with gdbus before any bus traffic occurs,
+         * so we get remote errors mapped correctly to their local counterparts.
+         * This error quark registration happens implicitly the first time the
+         * quark is used.
+         * Note that g_debug is never optimized away, only the output is suppressed.
+         */
+        g_debug ("GdmDBusUtils: Registered DBus error domain '%s'",
+                 g_quark_to_string (domain));
+}
diff --git a/daemon/gdm-dbus-util.h b/daemon/gdm-dbus-util.h
index 47654de25..32dc31963 100644
--- a/daemon/gdm-dbus-util.h
+++ b/daemon/gdm-dbus-util.h
@@ -35,4 +35,6 @@ gboolean gdm_dbus_get_pid_for_name (const char  *system_bus_name,
 gboolean gdm_dbus_get_uid_for_name (const char  *system_bus_name,
                                     uid_t       *out_uid,
                                     GError     **error);
+
+void gdm_dbus_error_ensure (GQuark domain);
 #endif
diff --git a/daemon/gdm-session.c b/daemon/gdm-session.c
index a6f00b66d..5c5903a49 100644
--- a/daemon/gdm-session.c
+++ b/daemon/gdm-session.c
@@ -3998,6 +3998,9 @@ gdm_session_class_init (GdmSessionClass *session_class)
                                                                FALSE,
                                                                G_PARAM_READWRITE | G_PARAM_CONSTRUCT | 
G_PARAM_STATIC_STRINGS));
 #endif
+
+        /* Ensure we can resolve errors */
+        gdm_dbus_error_ensure (GDM_SESSION_WORKER_ERROR);
 }
 
 GdmSession *