[tracker] libtracker-data: Improve error checks on REPLACE implementation

[Carlos Garnacho <carlosg src gnome org>]

commit a016c7b3e9a7a10fd94bc02ccda37a8bffc305de
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Dec 13 21:58:03 2016 +0100

    libtracker-data: Improve error checks on REPLACE implementation

 src/libtracker-data/tracker-db-interface-sqlite.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/libtracker-data/tracker-db-interface-sqlite.c 
b/src/libtracker-data/tracker-db-interface-sqlite.c
index df30a21..4c84d55 100644
--- a/src/libtracker-data/tracker-db-interface-sqlite.c
+++ b/src/libtracker-data/tracker-db-interface-sqlite.c
@@ -593,7 +593,7 @@ function_sparql_replace (sqlite3_context *context,
        TrackerDBReplaceFuncChecks *checks = &db_interface->replace_func_checks;
        gboolean store_regex = FALSE, store_replace_regex = FALSE;
        const gchar *input, *pattern, *replacement, *flags;
-       gchar *err_str, *output, *replaced = NULL, *unescaped = NULL;
+       gchar *err_str, *output = NULL, *replaced = NULL, *unescaped = NULL;
        GError *error = NULL;
        GRegexCompileFlags regex_flags = 0;
        GRegex *regex, *replace_regex;
@@ -716,13 +716,13 @@ function_sparql_replace (sqlite3_context *context,
        replaced = g_regex_replace (replace_regex,
                                    replacement, -1, 0, "\\\\g<\\1>", 0, &error);
 
-       if (replaced) {
+       if (!error) {
                /* All '\$' pairs are replaced by '$' */
                unescaped = g_regex_replace (checks->unescape,
                                             replaced, -1, 0, "$", 0, &error);
        }
 
-       if (unescaped) {
+       if (!error) {
                output = g_regex_replace (regex, input, -1, 0, unescaped, 0, &error);
        }