[evolution-data-server] Make EWebDAVSession soft-depend on ESourceWebdav extension

[Milan Crha <mcrha src gnome org>]

commit 69785aa84937e5bd893a6de4959c7c6730097d19
Author: Milan Crha <mcrha redhat com>
Date:   Fri Jul 21 09:27:25 2017 +0200

    Make EWebDAVSession soft-depend on ESourceWebdav extension
    
    The hard dependency on the ESourceWebdav extension could break
    discovery of GOA-defined accounts, like those for ownCloud,
    which run the discovery on the collection source, which may not have
    the ESourceWebdav extension defined at all.

 src/libedataserver/e-webdav-session.c |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)
---
diff --git a/src/libedataserver/e-webdav-session.c b/src/libedataserver/e-webdav-session.c
index f01471e..5c02efb 100644
--- a/src/libedataserver/e-webdav-session.c
+++ b/src/libedataserver/e-webdav-session.c
@@ -611,9 +611,9 @@ e_webdav_session_init (EWebDAVSession *webdav)
  * e_webdav_session_new:
  * @source: an #ESource
  *
- * Creates a new #EWebDAVSession associated with given @source. It's
- * a user's error to try to create the #EWebDAVSession for a source
- * which doesn't have #ESourceWebdav extension properly defined.
+ * Creates a new #EWebDAVSession associated with given @source.
+ * The #EWebDAVSession uses an #ESourceWebdav extension on certain
+ * places when it's defined for the @source.
  *
  * Returns: (transfer full): a new #EWebDAVSession; free it with g_object_unref(),
  *    when no longer needed.
@@ -624,7 +624,6 @@ EWebDAVSession *
 e_webdav_session_new (ESource *source)
 {
        g_return_val_if_fail (E_IS_SOURCE (source), NULL);
-       g_return_val_if_fail (e_source_has_extension (source, E_SOURCE_EXTENSION_WEBDAV_BACKEND), NULL);
 
        return g_object_new (E_TYPE_WEBDAV_SESSION,
                "source", source,
@@ -665,6 +664,12 @@ e_webdav_session_new_request (EWebDAVSession *webdav,
        source = e_soup_session_get_source (session);
        g_return_val_if_fail (E_IS_SOURCE (source), NULL);
 
+       if (!e_source_has_extension (source, E_SOURCE_EXTENSION_WEBDAV_BACKEND)) {
+               g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
+                       _("Cannot determine destination URL without WebDAV extension"));
+               return NULL;
+       }
+
        webdav_extension = e_source_get_extension (source, E_SOURCE_EXTENSION_WEBDAV_BACKEND);
        soup_uri = e_source_webdav_dup_soup_uri (webdav_extension);
 
@@ -1007,7 +1012,7 @@ e_webdav_session_replace_with_detailed_error (EWebDAVSession *webdav,
  *
  * Converts possibly path-only @href into a full URI under the @request_uri.
  * When the @request_uri is %NULL, the URI defined in associated #ESource is
- * used instead.
+ * used instead, taken from the #ESourceWebdav extension, if defined.
  *
  * Free the returned pointer with g_free(), when no longer needed.
  *
@@ -1036,6 +1041,9 @@ e_webdav_session_ensure_full_uri (EWebDAVSession *webdav,
                        source = e_soup_session_get_source (E_SOUP_SESSION (webdav));
                        g_return_val_if_fail (E_IS_SOURCE (source), NULL);
 
+                       if (!e_source_has_extension (source, E_SOURCE_EXTENSION_WEBDAV_BACKEND))
+                               return g_strdup (href);
+
                        webdav_extension = e_source_get_extension (source, E_SOURCE_EXTENSION_WEBDAV_BACKEND);
                        soup_uri = e_source_webdav_dup_soup_uri (webdav_extension);
                }