[evolution-data-server] Let child source with 'none' authentication method use collection source authentication

[Milan Crha <mcrha src gnome org>]

commit 6672b8236139bd6ef41ecb915f4c72e2a052dba5
Author: Milan Crha <mcrha redhat com>
Date:   Tue Dec 4 18:19:30 2018 +0100

    Let child source with 'none' authentication method use collection source authentication
    
    That might be the same as having set NULL authentication method.
    
    Related to https://gitlab.gnome.org/GNOME/evolution-ews/issues/27

 src/libedataserver/e-data-server-util.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/libedataserver/e-data-server-util.c b/src/libedataserver/e-data-server-util.c
index 47fd4d2ec..bd209c980 100644
--- a/src/libedataserver/e-data-server-util.c
+++ b/src/libedataserver/e-data-server-util.c
@@ -3259,11 +3259,13 @@ e_util_can_use_collection_as_credential_source (ESource *collection_source,
                        if (can_use_collection) {
                                gchar *method_source, *method_collection;
 
-                               /* Also check the method; if different, then rather not use the collection */
+                               /* Also check the method; if different, then rather not use the collection.
+                                  Consider 'none' method on the child as the same as the collection method. 
*/
                                method_source = e_source_authentication_dup_method (auth_source);
                                method_collection = e_source_authentication_dup_method (auth_collection);
 
                                can_use_collection = !method_source || !method_collection ||
+                                       g_ascii_strcasecmp (method_source, "none") == 0 ||
                                        g_ascii_strcasecmp (method_source, method_collection) == 0;
 
                                g_free (method_source);