# UNDF: TBD
--- a/src/modules/calendar/e-cal-shell-view-private.h
+++ b/src/modules/calendar/e-cal-shell-view-private.h
@@ -113,7 +113,8 @@ struct _ECalShellViewPrivate {
 	gint search_direction; /* negative value is backward, positive is forward, zero is error; in days */
 	GSList *search_hit_cache; /* pointers on time_t for matched events */
+	GHashTable *search_hit_cache_set; /* time_t values as gpointer keys for O(1) dedup */

 	/* Event/Task/Memo transferring */
 	gpointer transfer_alert; /* weak pointer to EAlert * */
--- a/src/modules/calendar/e-cal-shell-view-private.c
+++ b/src/modules/calendar/e-cal-shell-view-private.c
@@ -878,10 +878,14 @@ cal_searching_got_instance_cb (ICalComponent *icomp,
 	priv = gid->cal_shell_view->priv;
 	value = g_new (time_t, 1);
 	*value = start;
-	if (!g_slist_find_custom (priv->search_hit_cache, value, cal_time_t_ptr_compare))
+	if (!priv->search_hit_cache_set)
+		priv->search_hit_cache_set = g_hash_table_new (g_direct_hash, g_direct_equal);
+	if (!g_hash_table_contains (priv->search_hit_cache_set, GINT_TO_POINTER ((gint) start))) {
+		g_hash_table_add (priv->search_hit_cache_set, GINT_TO_POINTER ((gint) start));
 		priv->search_hit_cache = g_slist_append (priv->search_hit_cache, value);
-	else
+	} else {
 		g_free (value);
+	}

 	return TRUE;
 }
@@ -1271,6 +1275,10 @@ e_cal_shell_view_search_start (ECalShellView *cal_shell_view,
 	if (priv->search_hit_cache) {
 		g_slist_free_full (priv->search_hit_cache, g_free);
 		priv->search_hit_cache = NULL;
 	}
+	if (priv->search_hit_cache_set) {
+		g_hash_table_destroy (priv->search_hit_cache_set);
+		priv->search_hit_cache_set = NULL;
+	}

 	cal_iterate_searching (cal_shell_view);
 }
@@ -1300,6 +1308,10 @@ e_cal_shell_view_search_stop (ECalShellView *cal_shell_view)
 	if (priv->search_hit_cache) {
 		g_slist_free_full (priv->search_hit_cache, g_free);
 		priv->search_hit_cache = NULL;
 	}
+	if (priv->search_hit_cache_set) {
+		g_hash_table_destroy (priv->search_hit_cache_set);
+		priv->search_hit_cache_set = NULL;
+	}

 	priv->search_direction = 0;
 }