[tracker] libtracker-data: Plug parser leak on error

[Carlos Garnacho <carlosg src gnome org>]

commit 12e40a5fe525f87bd0e8ca1fb432b37d908d6fea
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Apr 17 13:39:22 2019 +0200

    libtracker-data: Plug parser leak on error
    
    We would leak the parsing tree accumulated thus far on errors. Good
    news is that it's potentially unlikely, bad news is that it's potentially
    big.

 src/libtracker-data/tracker-sparql-parser.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/libtracker-data/tracker-sparql-parser.c b/src/libtracker-data/tracker-sparql-parser.c
index d6cc6e532..8afee0587 100644
--- a/src/libtracker-data/tracker-sparql-parser.c
+++ b/src/libtracker-data/tracker-sparql-parser.c
@@ -741,6 +741,7 @@ tracker_grammar_parser_apply (TrackerGrammarParser      *parser,
 
        if (!tracker_grammar_parser_read (parser, &state)) {
                tracker_parser_state_propagate_error (&state, error);
+               tracker_node_tree_free (state.node_tree);
                g_free (state.rule_states.rules);
                return NULL;
        }