[evolution] I#400 - [To Do Bar] False runtime warning with 'Show Tasks without Due date' set

[Milan Crha <mcrha src gnome org>]

commit 556384f863e618f4030689e0d96b26a1ca91b378
Author: Milan Crha <mcrha redhat com>
Date:   Tue May 7 10:08:46 2019 +0200

    I#400 - [To Do Bar] False runtime warning with 'Show Tasks without Due date' set
    
    Closes https://gitlab.gnome.org/GNOME/evolution/issues/400

 src/calendar/gui/e-to-do-pane.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/src/calendar/gui/e-to-do-pane.c b/src/calendar/gui/e-to-do-pane.c
index a9730a8ee8..4cea7d8a99 100644
--- a/src/calendar/gui/e-to-do-pane.c
+++ b/src/calendar/gui/e-to-do-pane.c
@@ -897,6 +897,11 @@ etdp_add_component (EToDoPane *to_do_pane,
        ident = component_ident_new (client, id->uid, id->rid);
 
        new_root_paths = etdp_get_component_root_paths (to_do_pane, client, comp, default_zone);
+       /* This can happen with "Show Tasks without Due date", which returns
+          basically all tasks, even with Due date in the future, out of
+          the interval used by the To Do bar. */
+       if (!new_root_paths)
+               goto exit;
 
        new_references = etdp_merge_with_root_paths (to_do_pane, model, new_root_paths,
                g_hash_table_lookup (to_do_pane->priv->component_refs, ident));
@@ -972,6 +977,7 @@ etdp_add_component (EToDoPane *to_do_pane,
 
        g_hash_table_insert (to_do_pane->priv->component_refs, component_ident_copy (ident), new_references);
 
+ exit:
        component_ident_free (ident);
        e_cal_component_free_id (id);
        g_free (summary);