[evolution-ews] Bug 792190 - Fails to update offline GAL

[Milan Crha <mcrha src gnome org>]

commit dd2cee8b5f1cef6efbbef6100927b219d6372402
Author: Milan Crha <mcrha redhat com>
Date:   Thu Jan 4 14:26:56 2018 +0100

    Bug 792190 - Fails to update offline GAL

 src/server/e-ews-connection.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/src/server/e-ews-connection.c b/src/server/e-ews-connection.c
index 0751bd7..ab3b2dc 100644
--- a/src/server/e-ews-connection.c
+++ b/src/server/e-ews-connection.c
@@ -2484,7 +2484,12 @@ e_ews_connection_update_credentials (EEwsConnection *cnc,
        g_return_if_fail (E_IS_EWS_CONNECTION (cnc));
 
        if (credentials) {
-               e_ews_connection_set_password (cnc, e_named_parameters_get (credentials, 
E_SOURCE_CREDENTIAL_PASSWORD));
+               const gchar *password;
+
+               /* Update password only if it's provided, otherwise keep the previously set, if any */
+               password = e_named_parameters_get (credentials, E_SOURCE_CREDENTIAL_PASSWORD);
+               if (password && *password)
+                       e_ews_connection_set_password (cnc, password);
 
                if (e_named_parameters_get (credentials, E_SOURCE_CREDENTIAL_USERNAME)) {
                        CamelNetworkSettings *network_settings;