[gnome-calendar/mcatanzaro/#434: 2/2] Don't leave dangling pointers in the GcalEvent cache

[Michael Catanzaro <mcatanzaro src gnome org>]

commit a0fe45ec9923902a347d0fb4f2774078c73e9267
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Tue Jul 16 19:40:06 2019 -0500

    Don't leave dangling pointers in the GcalEvent cache
    
    The cache has an unowned pointer to the GcalEvent's UID. We need to
    update the cache with the GcalEvent's new UID to avoid use-after-free.
    
    Fixes #434

 src/core/gcal-event.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/src/core/gcal-event.c b/src/core/gcal-event.c
index a59bfd99..a54ae284 100644
--- a/src/core/gcal-event.c
+++ b/src/core/gcal-event.c
@@ -265,6 +265,9 @@ gcal_event_update_uid_internal (GcalEvent *self)
   id = e_cal_component_get_id (self->component);
 
   /* Clear the previous uid */
+  g_debug ("Removing '%s' (%p) from cache", self->uid, self);
+  g_hash_table_remove (event_cache, self->uid);
+
   g_clear_pointer (&self->uid, g_free);
 
   if (e_cal_component_id_get_rid (id) != NULL)
@@ -281,6 +284,9 @@ gcal_event_update_uid_internal (GcalEvent *self)
                                    e_cal_component_id_get_uid (id));
     }
 
+  g_debug ("Adding %s to the cache", self->uid);
+  g_hash_table_insert (event_cache, self->uid, self);
+
   e_cal_component_id_free (id);
   g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_UID]);
 }