[tracker/wip/carlosg/hashtable-ownership: 1/3] libtracker-data: Add extra reference to graphs HT when dealing with it

[Carlos Garnacho <carlosg src gnome org>]

commit 066c7390759fd89b14f351a089749ce3dd70118d
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Dec 5 23:18:30 2021 +0100

    libtracker-data: Add extra reference to graphs HT when dealing with it
    
    This hashtable may change under our feet, so it's a good idea to stick
    to a reference of it.

 src/libtracker-data/tracker-sparql.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql.c b/src/libtracker-data/tracker-sparql.c
index f6d42228a..1e238c71a 100644
--- a/src/libtracker-data/tracker-sparql.c
+++ b/src/libtracker-data/tracker-sparql.c
@@ -507,6 +507,7 @@ _append_resource_rowid_access_check (TrackerSparql *sparql)
                                       l->data);
        }
 
+       g_hash_table_unref (graphs);
        g_list_free (names);
 }
 
@@ -710,9 +711,9 @@ tracker_sparql_get_effective_graphs (TrackerSparql *sparql)
                        }
                }
 
-               return sparql->policy.filtered_graphs;
+               return g_hash_table_ref (sparql->policy.filtered_graphs);
        } else {
-               return graphs;
+               return g_hash_table_ref (graphs);
        }
 }
 
@@ -767,6 +768,7 @@ _append_union_graph_with_clause (TrackerSparql *sparql,
        }
 
        _append_string (sparql, ") ");
+       g_hash_table_unref (graphs);
 }
 
 static void
@@ -868,6 +870,7 @@ tracker_sparql_add_union_graph_subquery_for_named_graphs (TrackerSparql *sparql)
        _append_string (sparql, ") ");
 
        tracker_sparql_swap_builder (sparql, old);
+       g_hash_table_unref (graphs);
 }
 
 static gint
@@ -880,9 +883,11 @@ tracker_sparql_find_graph (TrackerSparql *sparql,
        effective_graphs = tracker_sparql_get_effective_graphs (sparql);
        if (!effective_graphs ||
            !g_hash_table_contains (effective_graphs, name)) {
+               g_hash_table_unref (effective_graphs);
                return 0;
        }
 
+       g_hash_table_unref (effective_graphs);
        in_transaction = sparql->query_type == TRACKER_SPARQL_QUERY_UPDATE;
 
        return tracker_data_manager_find_graph (sparql->data_manager, name,
@@ -1591,6 +1596,8 @@ tracker_sparql_add_fts_subquery (TrackerSparql         *sparql,
                        _append_literal_sql (sparql, binding);
                        _append_string (sparql, ", '\"', ' ') || '\"*'");
                }
+
+               g_hash_table_unref (graphs);
        }
 
        _append_string (sparql, ") ");
@@ -3992,6 +3999,8 @@ translate_Clear (TrackerSparql  *sparql,
 
                        while (g_hash_table_iter_next (&iter, (gpointer *) &graph, NULL))
                                graphs = g_list_prepend (graphs, (gpointer) graph);
+
+                       g_hash_table_unref (ht);
                }
        } else {
                graph = tracker_token_get_idstring (&sparql->current_state->graph);
@@ -4048,6 +4057,8 @@ translate_Drop (TrackerSparql  *sparql,
 
                        while (g_hash_table_iter_next (&iter, (gpointer *) &graph, NULL))
                                graphs = g_list_prepend (graphs, g_strdup (graph));
+
+                       g_hash_table_unref (ht);
                }
        } else {
                graph = tracker_token_get_idstring (&sparql->current_state->graph);