[tracker/tracker-2.2: 10/32] libtracker-data: Ensure triples cursor is entirely reset on filter()

[Sam Thursfield <sthursfield src gnome org>]

commit 9c9e3f593584580d2aae9dff015d1adcb3551a5f
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Jun 8 15:59:17 2019 +0200

    libtracker-data: Ensure triples cursor is entirely reset on filter()
    
    The cursor may actually be reused multiple times for different values,
    in which case we'd get filter() called again on it. Ensure the cursor
    is properly reset so it can handle later items as if brand new.

 src/libtracker-data/tracker-vtab-triples.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)
---
diff --git a/src/libtracker-data/tracker-vtab-triples.c b/src/libtracker-data/tracker-vtab-triples.c
index 92a5ff86c..78cae40cb 100644
--- a/src/libtracker-data/tracker-vtab-triples.c
+++ b/src/libtracker-data/tracker-vtab-triples.c
@@ -98,17 +98,24 @@ tracker_triples_vtab_free (gpointer data)
 }
 
 static void
-tracker_triples_cursor_free (gpointer data)
+tracker_triples_cursor_reset (TrackerTriplesCursor *cursor)
 {
-       TrackerTriplesCursor *cursor = data;
-
-       if (cursor->stmt)
-               sqlite3_finalize (cursor->stmt);
-
+       g_clear_pointer (&cursor->stmt, sqlite3_finalize);
        g_clear_pointer (&cursor->match.graph, sqlite3_value_free);
        g_clear_pointer (&cursor->match.subject, sqlite3_value_free);
        g_clear_pointer (&cursor->match.predicate, sqlite3_value_free);
-       g_list_free (cursor->properties);
+       g_clear_pointer (&cursor->properties, g_list_free);
+       cursor->match.idxFlags = 0;
+       cursor->rowid = 0;
+       cursor->finished = FALSE;
+}
+
+static void
+tracker_triples_cursor_free (gpointer data)
+{
+       TrackerTriplesCursor *cursor = data;
+
+       tracker_triples_cursor_reset (cursor);
        g_free (cursor);
 }
 
@@ -414,6 +421,8 @@ triples_filter (sqlite3_vtab_cursor  *vtab_cursor,
        TrackerTriplesCursor *cursor = (TrackerTriplesCursor *) vtab_cursor;
        int rc;
 
+       tracker_triples_cursor_reset (cursor);
+
        if (idx & IDX_COL_GRAPH) {
                int idx = idx_str[COL_GRAPH];
                cursor->match.graph = sqlite3_value_dup (argv[idx]);