[evolution-data-server] [EWebDAVDiscover] Prevent crash on GError use in gio functions

[Milan Crha <mcrha src gnome org>]

commit cd643b8d7c0934d80bb5a715e36f2aa2966da7d6
Author: Milan Crha <mcrha redhat com>
Date:   Mon Apr 29 14:29:25 2019 +0200

    [EWebDAVDiscover] Prevent crash on GError use in gio functions
    
    When the server returns invalid address and the call fails then
    the wdd->error could be set. Retrying another href with this set
    error can be caught by gio's assertions like this:
    
    GLib-Net:ERROR:../tls/gnutls/gtlsconnection-gnutls.c:910:end_gnutls_io: assertion failed: (!error || 
!*error)

 src/libedataserver/e-webdav-discover.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)
---
diff --git a/src/libedataserver/e-webdav-discover.c b/src/libedataserver/e-webdav-discover.c
index c7944bb10..16ac99ca6 100644
--- a/src/libedataserver/e-webdav-discover.c
+++ b/src/libedataserver/e-webdav-discover.c
@@ -119,19 +119,25 @@ e_webdav_discover_traverse_propfind_response_cb (EWebDAVSession *webdav,
                                home_set_href = e_xml_xpath_eval_as_string (xpath_ctx, 
"%s/A:addressbook-home-set/D:href[%d]", xpath_prop_prefix, ii + 1);
                                if (home_set_href && *home_set_href) {
                                        GSList *resources = NULL;
+                                       GError *local_error = NULL;
 
                                        full_href = e_webdav_session_ensure_full_uri (webdav, request_uri, 
home_set_href);
                                        if (full_href && *full_href && !g_hash_table_contains 
(wdd->covered_hrefs, full_href) &&
                                            e_webdav_session_list_sync (webdav, full_href, 
E_WEBDAV_DEPTH_THIS_AND_CHILDREN,
                                                E_WEBDAV_LIST_SUPPORTS | E_WEBDAV_LIST_DISPLAY_NAME | 
E_WEBDAV_LIST_DESCRIPTION |
                                                E_WEBDAV_LIST_COLOR | E_WEBDAV_LIST_ONLY_ADDRESSBOOK,
-                                               &resources, wdd->cancellable, wdd->error)) {
+                                               &resources, wdd->cancellable, &local_error)) {
                                                e_webdav_discover_split_resources (wdd, resources);
                                                g_slist_free_full (resources, e_webdav_resource_free);
                                        }
 
                                        if (full_href && *full_href)
                                                g_hash_table_insert (wdd->covered_hrefs, g_strdup 
(full_href), GINT_TO_POINTER (1));
+
+                                       if (local_error && wdd->error && !*wdd->error)
+                                               g_propagate_error (wdd->error, local_error);
+                                       else
+                                               g_clear_error (&local_error);
                                }
 
                                g_free (home_set_href);
@@ -153,19 +159,25 @@ e_webdav_discover_traverse_propfind_response_cb (EWebDAVSession *webdav,
                                home_set_href = e_xml_xpath_eval_as_string (xpath_ctx, 
"%s/C:calendar-home-set/D:href[%d]", xpath_prop_prefix, ii + 1);
                                if (home_set_href && *home_set_href) {
                                        GSList *resources = NULL;
+                                       GError *local_error = NULL;
 
                                        full_href = e_webdav_session_ensure_full_uri (webdav, request_uri, 
home_set_href);
                                        if (full_href && *full_href && !g_hash_table_contains 
(wdd->covered_hrefs, full_href) &&
                                            e_webdav_session_list_sync (webdav, full_href, 
E_WEBDAV_DEPTH_THIS_AND_CHILDREN,
                                                E_WEBDAV_LIST_SUPPORTS | E_WEBDAV_LIST_DISPLAY_NAME | 
E_WEBDAV_LIST_DESCRIPTION |
                                                E_WEBDAV_LIST_COLOR | E_WEBDAV_LIST_ONLY_CALENDAR,
-                                               &resources, wdd->cancellable, wdd->error)) {
+                                               &resources, wdd->cancellable, &local_error)) {
                                                e_webdav_discover_split_resources (wdd, resources);
                                                g_slist_free_full (resources, e_webdav_resource_free);
                                        }
 
                                        if (full_href && *full_href)
                                                g_hash_table_insert (wdd->covered_hrefs, g_strdup 
(full_href), GINT_TO_POINTER (1));
+
+                                       if (local_error && wdd->error && !*wdd->error)
+                                               g_propagate_error (wdd->error, local_error);
+                                       else
+                                               g_clear_error (&local_error);
                                }
 
                                g_free (home_set_href);
@@ -241,18 +253,24 @@ e_webdav_discover_traverse_propfind_response_cb (EWebDAVSession *webdav,
 
                if (is_calendar || is_addressbook) {
                        GSList *resources = NULL;
+                       GError *local_error = NULL;
 
                        if (!g_hash_table_contains (wdd->covered_hrefs, href) &&
                            !g_cancellable_is_cancelled (wdd->cancellable) &&
                            e_webdav_session_list_sync (webdav, href, E_WEBDAV_DEPTH_THIS,
                                E_WEBDAV_LIST_SUPPORTS | E_WEBDAV_LIST_DISPLAY_NAME | 
E_WEBDAV_LIST_DESCRIPTION | E_WEBDAV_LIST_COLOR |
                                (is_calendar ? E_WEBDAV_LIST_ONLY_CALENDAR : 0) | (is_addressbook ? 
E_WEBDAV_LIST_ONLY_ADDRESSBOOK : 0),
-                               &resources, wdd->cancellable, wdd->error)) {
+                               &resources, wdd->cancellable, &local_error)) {
                                e_webdav_discover_split_resources (wdd, resources);
                                g_slist_free_full (resources, e_webdav_resource_free);
                        }
 
                        g_hash_table_insert (wdd->covered_hrefs, g_strdup (href), GINT_TO_POINTER (1));
+
+                       if (local_error && wdd->error && !*wdd->error)
+                               g_propagate_error (wdd->error, local_error);
+                       else
+                               g_clear_error (&local_error);
                }
        }
 
@@ -267,6 +285,7 @@ e_webdav_discover_propfind_uri_sync (EWebDAVSession *webdav,
 {
        EXmlDocument *xml;
        gboolean success;
+       GError *local_error = NULL;
 
        g_return_val_if_fail (E_IS_WEBDAV_SESSION (webdav), FALSE);
        g_return_val_if_fail (wdd != NULL, FALSE);
@@ -302,10 +321,15 @@ e_webdav_discover_propfind_uri_sync (EWebDAVSession *webdav,
        e_xml_document_end_element (xml); /* prop */
 
        success = e_webdav_session_propfind_sync (webdav, uri, E_WEBDAV_DEPTH_THIS, xml,
-               e_webdav_discover_traverse_propfind_response_cb, wdd, wdd->cancellable, wdd->error);
+               e_webdav_discover_traverse_propfind_response_cb, wdd, wdd->cancellable, &local_error);
 
        g_clear_object (&xml);
 
+       if (local_error && wdd->error && !*wdd->error)
+               g_propagate_error (wdd->error, local_error);
+       else
+               g_clear_error (&local_error);
+
        return success;
 }