Automatically strip D-Bus info from error messages.

I mistakenly assumed code generated by the gdbus-codegen tool would
automatically strip off the D-Bus error name from error messages, but
that apparently is not possible according to my discussion with David
Zeuthen in [1], since it would break g_dbus_error_is_remote_error().

Distinguishing between local and remote errors strikes me as a rarely
needed corner case, and is certainly not worth the extra step imposed
on applications when dealing with something as fundamental as GError.

This commit prevents the D-Bus error name from leaking through in any
Evolution-Data-Server client-facing library functions.

Also rename any stack-allocated GError pointers to 'local_error' to
help distinguish them from GError "out" parameters which are always
named 'error'.  This is just to improve variable name consistency.

[1] https://bugzilla.gnome.org/697819

2 files changed, 167 insertions, 114 deletions

diff --git a/libedataserver/e-source-registry.c b/libedataserver/e-source-registry.c
index 6c4f2fdad..5ad52cbd3 100644
--- a/libedataserver/e-source-registry.c
+++ b/libedataserver/e-source-registry.c
@@ -125,7 +125,6 @@ struct _AuthContext {
 	ESourceAuthenticationResult auth_result;
 	GcrSecretExchange *secret_exchange;
 	gboolean authenticating;
-	gboolean success;
 	GError **error;
 };
 
@@ -564,24 +563,24 @@ source_registry_new_source (ESourceRegistry *registry,
 	GMainContext *main_context;
 	ESource *source;
 	const gchar *object_path;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	/* We don't want the ESource emitting "changed" signals from
 	 * the manager thread, so we pass it the same main context the
 	 * registry uses for scheduling signal emissions. */
 	main_context = registry->priv->main_context;
-	source = e_source_new (dbus_object, main_context, &error);
+	source = e_source_new (dbus_object, main_context, &local_error);
 	object_path = g_dbus_object_get_object_path (dbus_object);
 
 	/* The likelihood of an error here is slim, so it's
 	 * sufficient to just print a warning if one occurs. */
-	if (error != NULL) {
+	if (local_error != NULL) {
 		g_warn_if_fail (source == NULL);
 		g_critical (
 			"ESourceRegistry: Failed to create a "
 			"data source object for path '%s': %s",
-			object_path, error->message);
-		g_error_free (error);
+			object_path, local_error->message);
+		g_error_free (local_error);
 		return NULL;
 	}
 
@@ -1048,6 +1047,7 @@ source_registry_initable_init (GInitable *initable,
 {
 	ESourceRegistry *registry;
 	ThreadClosure *closure;
+	GError *local_error = NULL;
 
 	registry = E_SOURCE_REGISTRY (initable);
 
@@ -1082,6 +1082,7 @@ source_registry_initable_init (GInitable *initable,
 
 	/* Check for error in the manager thread. */
 	if (closure->error != NULL) {
+		g_dbus_error_strip_remote_error (closure->error);
 		g_propagate_error (error, closure->error);
 		closure->error = NULL;
 		return FALSE;
@@ -1115,10 +1116,13 @@ source_registry_initable_init (GInitable *initable,
 			G_DBUS_PROXY_FLAGS_NONE,
 			SOURCES_DBUS_SERVICE_NAME,
 			DBUS_OBJECT_PATH,
-			cancellable, error);
+			cancellable, &local_error);
 
-	if (registry->priv->dbus_source_manager == NULL)
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
 		return FALSE;
+	}
 
 	/* Allow authentication prompts for all exported data sources
 	 * when a new EDBusSourceManagerProxy is created.  The thought
@@ -1459,7 +1463,7 @@ source_registry_authenticate_thread (GSimpleAsyncResult *simple,
                                      GCancellable *cancellable)
 {
 	AsyncContext *async_context;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	async_context = g_simple_async_result_get_op_res_gpointer (simple);
 
@@ -1467,10 +1471,10 @@ source_registry_authenticate_thread (GSimpleAsyncResult *simple,
 		E_SOURCE_REGISTRY (object),
 		async_context->source,
 		async_context->auth,
-		cancellable, &error);
+		cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 /* Helper for e_source_registry_authenticate_sync() */
@@ -1507,7 +1511,6 @@ source_registry_authenticate_respond_cb (AuthContext *auth_context)
 			auth_context->dbus_auth,
 			NULL, &non_fatal_error);
 		g_main_loop_quit (auth_context->main_loop);
-		auth_context->success = FALSE;
 
 	/* If an error occurred while attempting to authenticate,
 	 * tell the server to cancel the authentication session. */
@@ -1517,7 +1520,6 @@ source_registry_authenticate_respond_cb (AuthContext *auth_context)
 			auth_context->cancellable,
 			&non_fatal_error);
 		g_main_loop_quit (auth_context->main_loop);
-		auth_context->success = FALSE;
 
 	/* If the password was accepted, let the server know so it
 	 * can close any authentication dialogs and save the user
@@ -1528,7 +1530,6 @@ source_registry_authenticate_respond_cb (AuthContext *auth_context)
 			auth_context->cancellable,
 			&non_fatal_error);
 		g_main_loop_quit (auth_context->main_loop);
-		auth_context->success = TRUE;
 
 	/* If the password was rejected, let the server know so it can
 	 * indicate failure and request a different password, and then
@@ -1543,6 +1544,7 @@ source_registry_authenticate_respond_cb (AuthContext *auth_context)
 	/* Leave breadcrumbs if something went wrong,
 	 * but don't fail the whole operation over it. */
 	if (non_fatal_error != NULL) {
+		g_dbus_error_strip_remote_error (non_fatal_error);
 		g_warning ("%s: %s", G_STRFUNC, non_fatal_error->message);
 		g_error_free (non_fatal_error);
 	}
@@ -1621,7 +1623,6 @@ source_registry_authenticate_dismissed_cb (EDBusAuthenticator *dbus_auth,
 	}
 
 	g_main_loop_quit (auth_context->main_loop);
-	auth_context->success = FALSE;
 }
 
 /* Helper for e_source_registry_authenticate_sync() */
@@ -1638,7 +1639,7 @@ source_registry_call_authenticate_for_source (ESourceRegistry *registry,
 	gchar *prompt_title = NULL;
 	gchar *prompt_message = NULL;
 	gchar *prompt_description = NULL;
-	gboolean success;
+	GError *local_error = NULL;
 
 	g_object_ref (source);
 
@@ -1685,10 +1686,10 @@ source_registry_call_authenticate_for_source (ESourceRegistry *registry,
 		&prompt_message,
 		&prompt_description);
 
-	success = e_dbus_source_manager_call_authenticate_sync (
+	e_dbus_source_manager_call_authenticate_sync (
 		registry->priv->dbus_source_manager, uid,
 		prompt_title, prompt_message, prompt_description,
-		out_object_path, cancellable, error);
+		out_object_path, cancellable, &local_error);
 
 	g_free (prompt_title);
 	g_free (prompt_message);
@@ -1696,7 +1697,13 @@ source_registry_call_authenticate_for_source (ESourceRegistry *registry,
 
 	g_object_unref (source);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /**
@@ -1735,7 +1742,7 @@ e_source_registry_authenticate_sync (ESourceRegistry *registry,
 	EDBusAuthenticator *dbus_auth;
 	gchar *encryption_key;
 	gchar *object_path = NULL;
-	gboolean success;
+	GError *local_error = NULL;
 
 	g_return_val_if_fail (E_IS_SOURCE_REGISTRY (registry), FALSE);
 	g_return_val_if_fail (E_IS_SOURCE (source), FALSE);
@@ -1744,11 +1751,13 @@ e_source_registry_authenticate_sync (ESourceRegistry *registry,
 	/* This extracts authentication prompt details for the ESource
 	 * before initiating an authentication session with the server,
 	 * so split it out of the main algorithm for clarity's sake. */
-	success = source_registry_call_authenticate_for_source (
-		registry, auth, source, &object_path, cancellable, error);
+	source_registry_call_authenticate_for_source (
+		registry, auth, source, &object_path,
+		cancellable, &local_error);
 
-	if (!success) {
+	if (local_error != NULL) {
 		g_warn_if_fail (object_path == NULL);
+		g_propagate_error (error, local_error);
 		return FALSE;
 	}
 
@@ -1761,20 +1770,23 @@ e_source_registry_authenticate_sync (ESourceRegistry *registry,
 		G_BUS_TYPE_SESSION,
 		G_DBUS_PROXY_FLAGS_NONE,
 		SOURCES_DBUS_SERVICE_NAME,
-		object_path, cancellable, error);
+		object_path, cancellable, &local_error);
 
 	g_free (object_path);
 
-	if (dbus_auth == NULL) {
-		success = FALSE;
+	/* Sanity check. */
+	g_return_val_if_fail (
+		((dbus_auth != NULL) && (local_error == NULL)) ||
+		((dbus_auth == NULL) && (local_error != NULL)), FALSE);
+
+	if (local_error != NULL)
 		goto exit;
-	}
 
 	auth_context = g_slice_new0 (AuthContext);
 	auth_context->auth = g_object_ref (auth);
 	auth_context->dbus_auth = dbus_auth;  /* takes ownership */
 	auth_context->main_loop = g_main_loop_new (main_context, FALSE);
-	auth_context->error = error;
+	auth_context->error = &local_error;
 
 	/* This just needs to be something other than
 	 * E_SOURCE_AUTHENTICATION_ERROR so we don't trip
@@ -1804,15 +1816,13 @@ e_source_registry_authenticate_sync (ESourceRegistry *registry,
 	 * authentication session.  This must happen AFTER we've
 	 * connected to the response signal since the server may
 	 * already have a response ready and waiting for us. */
-	success = e_dbus_authenticator_call_ready_sync (
-		dbus_auth, encryption_key, cancellable, error);
+	e_dbus_authenticator_call_ready_sync (
+		dbus_auth, encryption_key, cancellable, &local_error);
 
 	g_free (encryption_key);
 
-	if (success) {
+	if (local_error == NULL)
 		g_main_loop_run (auth_context->main_loop);
-		success = auth_context->success;
-	}
 
 	auth_context_free (auth_context);
 
@@ -1826,7 +1836,13 @@ exit:
 
 	g_main_context_unref (main_context);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /**
@@ -1929,17 +1945,17 @@ source_registry_commit_source_thread (GSimpleAsyncResult *simple,
                                       GCancellable *cancellable)
 {
 	AsyncContext *async_context;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	async_context = g_simple_async_result_get_op_res_gpointer (simple);
 
 	e_source_registry_commit_source_sync (
 		E_SOURCE_REGISTRY (object),
 		async_context->source,
-		cancellable, &error);
+		cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 /**
@@ -2100,17 +2116,17 @@ source_registry_create_sources_thread (GSimpleAsyncResult *simple,
                                        GCancellable *cancellable)
 {
 	AsyncContext *async_context;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	async_context = g_simple_async_result_get_op_res_gpointer (simple);
 
 	e_source_registry_create_sources_sync (
 		E_SOURCE_REGISTRY (object),
 		async_context->list_of_sources,
-		cancellable, &error);
+		cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 /* Helper for e_source_registry_create_sources_sync() */
@@ -2185,7 +2201,7 @@ e_source_registry_create_sources_sync (ESourceRegistry *registry,
 	GVariant *variant;
 	GList *link;
 	gulong object_added_id;
-	gboolean success;
+	GError *local_error = NULL;
 
 	g_return_val_if_fail (E_IS_SOURCE_REGISTRY (registry), FALSE);
 
@@ -2225,9 +2241,9 @@ e_source_registry_create_sources_sync (ESourceRegistry *registry,
 		create_context);
 
 	/* This function sinks the floating GVariant reference. */
-	success = e_dbus_source_manager_call_create_sources_sync (
+	e_dbus_source_manager_call_create_sources_sync (
 		registry->priv->dbus_source_manager,
-		variant, cancellable, error);
+		variant, cancellable, &local_error);
 
 	g_variant_builder_clear (&builder);
 
@@ -2235,7 +2251,7 @@ e_source_registry_create_sources_sync (ESourceRegistry *registry,
 	 * But also set a short timeout to avoid getting stuck here in
 	 * case the registry service adds sources to its orphan table,
 	 * which prevents them from being exported over D-Bus. */
-	if (success) {
+	if (local_error == NULL) {
 		GSource *timeout_source;
 
 		timeout_source = g_timeout_source_new_seconds (2);
@@ -2256,7 +2272,13 @@ e_source_registry_create_sources_sync (ESourceRegistry *registry,
 	g_main_context_pop_thread_default (create_context->main_context);
 	create_context_free (create_context);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /**
diff --git a/libedataserver/e-source.c b/libedataserver/e-source.c
index 5f9d8c84d..365974e10 100644
--- a/libedataserver/e-source.c
+++ b/libedataserver/e-source.c
@@ -387,7 +387,7 @@ source_set_property_from_key_file (GObject *object,
 {
 	gchar *key;
 	GValue *value;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	value = g_slice_new0 (GValue);
 	key = e_source_parameter_to_key (pspec->name);
@@ -401,8 +401,8 @@ source_set_property_from_key_file (GObject *object,
 		gint v_int;
 
 		v_int = g_key_file_get_integer (
-			key_file, group_name, key, &error);
-		if (error == NULL) {
+			key_file, group_name, key, &local_error);
+		if (local_error == NULL) {
 			g_value_init (value, G_TYPE_INT);
 			g_value_set_int (value, v_int);
 		}
@@ -411,8 +411,8 @@ source_set_property_from_key_file (GObject *object,
 		gint64 v_int64;
 
 		v_int64 = g_key_file_get_int64 (
-			key_file, group_name, key, &error);
-		if (error == NULL) {
+			key_file, group_name, key, &local_error);
+		if (local_error == NULL) {
 			g_value_init (value, G_TYPE_INT64);
 			g_value_set_int64 (value, v_int64);
 		}
@@ -422,8 +422,8 @@ source_set_property_from_key_file (GObject *object,
 		gchar *v_str;
 
 		v_str = g_key_file_get_string (
-			key_file, group_name, key, &error);
-		if (error == NULL) {
+			key_file, group_name, key, &local_error);
+		if (local_error == NULL) {
 			v_uint64 = g_ascii_strtoull (v_str, NULL, 16);
 
 			g_value_init (value, G_TYPE_UINT64);
@@ -436,8 +436,8 @@ source_set_property_from_key_file (GObject *object,
 		gboolean v_boolean;
 
 		v_boolean = g_key_file_get_boolean (
-			key_file, group_name, key, &error);
-		if (error == NULL) {
+			key_file, group_name, key, &local_error);
+		if (local_error == NULL) {
 			g_value_init (value, G_TYPE_BOOLEAN);
 			g_value_set_boolean (value, v_boolean);
 		}
@@ -446,8 +446,8 @@ source_set_property_from_key_file (GObject *object,
 		gchar *nick;
 
 		nick = g_key_file_get_string (
-			key_file, group_name, key, &error);
-		if (error == NULL) {
+			key_file, group_name, key, &local_error);
+		if (local_error == NULL) {
 			GParamSpecEnum *enum_pspec;
 			GEnumValue *enum_value;
 
@@ -466,8 +466,8 @@ source_set_property_from_key_file (GObject *object,
 		gdouble v_double;
 
 		v_double = g_key_file_get_double (
-			key_file, group_name, key, &error);
-		if (error == NULL) {
+			key_file, group_name, key, &local_error);
+		if (local_error == NULL) {
 			g_value_init (value, G_TYPE_DOUBLE);
 			g_value_set_double (value, v_double);
 		}
@@ -477,8 +477,8 @@ source_set_property_from_key_file (GObject *object,
 
 		/* Get the localized string if present. */
 		v_string = g_key_file_get_locale_string (
-			key_file, group_name, key, NULL, &error);
-		if (error == NULL) {
+			key_file, group_name, key, NULL, &local_error);
+		if (local_error == NULL) {
 			g_value_init (value, G_TYPE_STRING);
 			g_value_take_string (value, v_string);
 		}
@@ -487,8 +487,8 @@ source_set_property_from_key_file (GObject *object,
 		gchar **strv;
 
 		strv = g_key_file_get_string_list (
-			key_file, group_name, key, NULL, &error);
-		if (error == NULL) {
+			key_file, group_name, key, NULL, &local_error);
+		if (local_error == NULL) {
 			g_value_init (value, G_TYPE_STRV);
 			g_value_take_boxed (value, strv);
 		}
@@ -498,8 +498,8 @@ source_set_property_from_key_file (GObject *object,
 
 		/* Create the GFile from the URI string. */
 		uri = g_key_file_get_locale_string (
-			key_file, group_name, key, NULL, &error);
-		if (error == NULL) {
+			key_file, group_name, key, NULL, &local_error);
+		if (local_error == NULL) {
 			GFile *file = NULL;
 			if (uri != NULL && *uri != '\0')
 				file = g_file_new_for_uri (uri);
@@ -516,10 +516,10 @@ source_set_property_from_key_file (GObject *object,
 
 	/* If a value could not be retrieved from the key
 	 * file, restore the property to its default value. */
-	if (error != NULL) {
+	if (local_error != NULL) {
 		g_value_init (value, pspec->value_type);
 		g_param_value_set_default (pspec, value);
-		g_error_free (error);
+		g_error_free (local_error);
 	}
 
 	if (G_IS_VALUE (value)) {
@@ -646,17 +646,18 @@ source_notify_dbus_data_cb (EDBusSource *dbus_source,
                             GParamSpec *pspec,
                             ESource *source)
 {
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	g_rec_mutex_lock (&source->priv->lock);
 
 	/* Since the source data came from a GKeyFile structure on the
 	 * server-side, this should never fail.  But we'll print error
 	 * messages to the terminal just in case. */
-	if (!source_parse_dbus_data (source, &error)) {
-		g_return_if_fail (error != NULL);
-		g_warning ("%s", error->message);
-		g_error_free (error);
+	source_parse_dbus_data (source, &local_error);
+
+	if (local_error != NULL) {
+		g_warning ("%s", local_error->message);
+		g_error_free (local_error);
 	}
 
 	g_rec_mutex_unlock (&source->priv->lock);
@@ -926,7 +927,7 @@ source_remove_sync (ESource *source,
 {
 	EDBusSourceRemovable *dbus_interface = NULL;
 	GDBusObject *dbus_object;
-	gboolean success;
+	GError *local_error = NULL;
 
 	dbus_object = e_source_ref_dbus_object (source);
 	if (dbus_object != NULL) {
@@ -945,12 +946,18 @@ source_remove_sync (ESource *source,
 		return FALSE;
 	}
 
-	success = e_dbus_source_removable_call_remove_sync (
-		dbus_interface, cancellable, error);
+	e_dbus_source_removable_call_remove_sync (
+		dbus_interface, cancellable, &local_error);
 
 	g_object_unref (dbus_interface);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /* Helper for source_remove() */
@@ -959,12 +966,12 @@ source_remove_thread (GSimpleAsyncResult *simple,
                       GObject *object,
                       GCancellable *cancellable)
 {
-	GError *error = NULL;
+	GError *local_error = NULL;
 
-	e_source_remove_sync (E_SOURCE (object), cancellable, &error);
+	e_source_remove_sync (E_SOURCE (object), cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 static void
@@ -1011,8 +1018,8 @@ source_write_sync (ESource *source,
 {
 	EDBusSourceWritable *dbus_interface = NULL;
 	GDBusObject *dbus_object;
-	gboolean success;
 	gchar *data;
+	GError *local_error = NULL;
 
 	dbus_object = e_source_ref_dbus_object (source);
 	if (dbus_object != NULL) {
@@ -1033,14 +1040,20 @@ source_write_sync (ESource *source,
 
 	data = e_source_to_string (source, NULL);
 
-	success = e_dbus_source_writable_call_write_sync (
-		dbus_interface, data, cancellable, error);
+	e_dbus_source_writable_call_write_sync (
+		dbus_interface, data, cancellable, &local_error);
 
 	g_free (data);
 
 	g_object_unref (dbus_interface);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /* Helper for source_write() */
@@ -1049,12 +1062,12 @@ source_write_thread (GSimpleAsyncResult *simple,
                      GObject *object,
                      GCancellable *cancellable)
 {
-	GError *error = NULL;
+	GError *local_error = NULL;
 
-	e_source_write_sync (E_SOURCE (object), cancellable, &error);
+	e_source_write_sync (E_SOURCE (object), cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 static void
@@ -1103,7 +1116,7 @@ source_remote_create_sync (ESource *source,
 	EDBusSourceRemoteCreatable *dbus_interface = NULL;
 	GDBusObject *dbus_object;
 	gchar *uid, *data;
-	gboolean success;
+	GError *local_error = NULL;
 
 	dbus_object = e_source_ref_dbus_object (source);
 	if (dbus_object != NULL) {
@@ -1126,15 +1139,21 @@ source_remote_create_sync (ESource *source,
 	uid = e_source_dup_uid (scratch_source);
 	data = e_source_to_string (scratch_source, NULL);
 
-	success = e_dbus_source_remote_creatable_call_create_sync (
-		dbus_interface, uid, data, cancellable, error);
+	e_dbus_source_remote_creatable_call_create_sync (
+		dbus_interface, uid, data, cancellable, &local_error);
 
 	g_free (data);
 	g_free (uid);
 
 	g_object_unref (dbus_interface);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /* Helper for source_remote_create() */
@@ -1144,17 +1163,17 @@ source_remote_create_thread (GSimpleAsyncResult *simple,
                              GCancellable *cancellable)
 {
 	AsyncContext *async_context;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	async_context = g_simple_async_result_get_op_res_gpointer (simple);
 
 	e_source_remote_create_sync (
 		E_SOURCE (object),
 		async_context->scratch_source,
-		cancellable, &error);
+		cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 static void
@@ -1210,7 +1229,7 @@ source_remote_delete_sync (ESource *source,
 {
 	EDBusSourceRemoteDeletable *dbus_interface = NULL;
 	GDBusObject *dbus_object;
-	gboolean success;
+	GError *local_error = NULL;
 
 	dbus_object = e_source_ref_dbus_object (source);
 	if (dbus_object != NULL) {
@@ -1230,12 +1249,18 @@ source_remote_delete_sync (ESource *source,
 		return FALSE;
 	}
 
-	success = e_dbus_source_remote_deletable_call_delete_sync (
-		dbus_interface, cancellable, error);
+	e_dbus_source_remote_deletable_call_delete_sync (
+		dbus_interface, cancellable, &local_error);
 
 	g_object_unref (dbus_interface);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /* Helper for source_remote_delete() */
@@ -1244,13 +1269,13 @@ source_remote_delete_thread (GSimpleAsyncResult *simple,
                              GObject *object,
                              GCancellable *cancellable)
 {
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	e_source_remote_delete_sync (
-		E_SOURCE (object), cancellable, &error);
+		E_SOURCE (object), cancellable, &local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 static void
@@ -1300,7 +1325,7 @@ source_get_oauth2_access_token_sync (ESource *source,
 {
 	EDBusSourceOAuth2Support *dbus_interface = NULL;
 	GDBusObject *dbus_object;
-	gboolean success;
+	GError *local_error = NULL;
 
 	dbus_object = e_source_ref_dbus_object (source);
 	if (dbus_object != NULL) {
@@ -1320,13 +1345,19 @@ source_get_oauth2_access_token_sync (ESource *source,
 		return FALSE;
 	}
 
-	success = e_dbus_source_oauth2_support_call_get_access_token_sync (
+	e_dbus_source_oauth2_support_call_get_access_token_sync (
 		dbus_interface, out_access_token,
-		out_expires_in, cancellable, error);
+		out_expires_in, cancellable, &local_error);
 
 	g_object_unref (dbus_interface);
 
-	return success;
+	if (local_error != NULL) {
+		g_dbus_error_strip_remote_error (local_error);
+		g_propagate_error (error, local_error);
+		return FALSE;
+	}
+
+	return TRUE;
 }
 
 /* Helper for source_get_oauth2_access_token() */
@@ -1336,7 +1367,7 @@ source_get_oauth2_access_token_thread (GSimpleAsyncResult *simple,
                                        GCancellable *cancellable)
 {
 	AsyncContext *async_context;
-	GError *error = NULL;
+	GError *local_error = NULL;
 
 	async_context = g_simple_async_result_get_op_res_gpointer (simple);
 
@@ -1344,10 +1375,10 @@ source_get_oauth2_access_token_thread (GSimpleAsyncResult *simple,
 		E_SOURCE (object), cancellable,
 		&async_context->access_token,
 		&async_context->expires_in,
-		&error);
+		&local_error);
 
-	if (error != NULL)
-		g_simple_async_result_take_error (simple, error);
+	if (local_error != NULL)
+		g_simple_async_result_take_error (simple, local_error);
 }
 
 static void