[tracker/wip/carlosg/portal: 124/141] libtracker-data: Add graph policy checks on FTS queries

[Carlos Garnacho <carlosg src gnome org>]

commit e60c25392b51a39ceac90c84d4b5b64e3f0cdc4c
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Jan 25 22:10:27 2020 +0100

    libtracker-data: Add graph policy checks on FTS queries
    
    This makes them properly filtered by constraints.

 src/libtracker-data/tracker-sparql.c | 66 +++++++++++++++++++++++-------------
 1 file changed, 43 insertions(+), 23 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql.c b/src/libtracker-data/tracker-sparql.c
index b3c031ea5..f05566183 100644
--- a/src/libtracker-data/tracker-sparql.c
+++ b/src/libtracker-data/tracker-sparql.c
@@ -698,6 +698,23 @@ tracker_sparql_get_effective_graphs (TrackerSparql *sparql)
        }
 }
 
+static void
+_append_empty_select (TrackerSparql *sparql,
+                      gint           n_elems)
+{
+       gint i;
+
+       _append_string (sparql, "SELECT ");
+
+       for (i = 0; i < n_elems; i++) {
+               if (i > 0)
+                       _append_string (sparql, ", ");
+               _append_string (sparql, "NULL ");
+       }
+
+       _append_string (sparql, "WHERE 0 ");
+}
+
 static void
 _append_union_graph_with_clause (TrackerSparql *sparql,
                                  const gchar   *table_name,
@@ -718,17 +735,7 @@ _append_union_graph_with_clause (TrackerSparql *sparql,
                                       "SELECT ID, %s 0 AS graph FROM \"main\".\"%s\" ",
                                       properties, table_name);
        } else {
-               gint i;
-
-               _append_string (sparql, "SELECT ");
-
-               for (i = 0; i < n_properties + 2; i++) {
-                       if (i > 0)
-                               _append_string (sparql, ", ");
-                       _append_string (sparql, "NULL ");
-               }
-
-               _append_string (sparql, "WHERE 0 ");
+               _append_empty_select (sparql, n_properties + 2);
        }
 
        g_hash_table_iter_init (&iter, graphs);
@@ -1379,6 +1386,7 @@ tracker_sparql_add_fts_subquery (TrackerSparql         *sparql,
        gchar *snippet_expression = NULL;
        GString *select_items;
        gchar *table_name;
+       gint n_properties;
 
        old = tracker_sparql_swap_builder (sparql, sparql->current_state.with_clauses);
 
@@ -1391,12 +1399,14 @@ tracker_sparql_add_fts_subquery (TrackerSparql         *sparql,
                                      sparql->current_state.fts_match_idx++);
        _append_string_printf (sparql, "\"%s\"(ID ", table_name);
        select_items = g_string_new ("SELECT ROWID");
+       n_properties = 1;
 
        if (tracker_token_get_variable (subject)) {
                _append_string (sparql, ",\"ftsRank\", \"ftsOffsets\" ");
                g_string_append (select_items, ",rank, tracker_offsets(fts5) ");
 
                _append_string (sparql, ",\"ftsSnippet\" ");
+               n_properties += 3;
 
                if (introspect_fts_snippet (sparql, tracker_token_get_variable (subject),
                                            &snippet_expression, NULL)) {
@@ -1408,28 +1418,38 @@ tracker_sparql_add_fts_subquery (TrackerSparql         *sparql,
                }
        }
 
-       if (!tracker_token_get_literal (graph))
+       if (!tracker_token_get_literal (graph)) {
                _append_string (sparql, ", graph");
+               n_properties++;
+       }
 
        _append_string (sparql, ") AS (");
 
        if (tracker_token_get_literal (graph)) {
-               _append_string_printf (sparql,
-                                      "%s FROM \"%s\".\"fts5\" "
-                                      "WHERE fts5 = ",
-                                      select_items->str,
-                                      tracker_token_get_idstring (graph));
-               _append_literal_sql (sparql, binding);
+               if (tracker_sparql_find_graph (sparql, tracker_token_get_idstring (graph))) {
+                       _append_string_printf (sparql,
+                                              "%s FROM \"%s\".\"fts5\" "
+                                              "WHERE fts5 = ",
+                                              select_items->str,
+                                              tracker_token_get_idstring (graph));
+                       _append_literal_sql (sparql, binding);
+               } else {
+                       _append_empty_select (sparql, n_properties);
+               }
        } else {
                gpointer graph_name, graph_id;
                GHashTable *graphs;
                GHashTableIter iter;
 
-               _append_string_printf (sparql,
-                                      "%s, 0 FROM \"main\".\"fts5\" "
-                                      "WHERE fts5 = ",
-                                      select_items->str);
-               _append_literal_sql (sparql, binding);
+               if (!sparql->policy.filter_unnamed_graph) {
+                       _append_string_printf (sparql,
+                                              "%s, 0 FROM \"main\".\"fts5\" "
+                                              "WHERE fts5 = ",
+                                              select_items->str);
+                       _append_literal_sql (sparql, binding);
+               } else {
+                       _append_empty_select (sparql, n_properties);
+               }
 
                graphs = tracker_sparql_get_effective_graphs (sparql);
                g_hash_table_iter_init (&iter, graphs);