[tracker] libtracker-common: String to date conversion to return with GError when null string

[Andres Gomez <agomez src gnome org>]

commit b97e8db836346b97056b07fd01d9e15e2713b3a5
Author: Andres Gomez <andres gomez jolla com>
Date:   Sat Jul 18 01:03:42 2015 +0300

    libtracker-common: String to date conversion to return with GError when null string
    
    Previously we were failing with a GLIB CRITICAL.
    Now, return gentlier and with a filled GError.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=752544

 src/libtracker-common/tracker-date-time.c |    9 ++++++---
 src/libtracker-common/tracker-date-time.h |    3 ++-
 2 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/src/libtracker-common/tracker-date-time.c b/src/libtracker-common/tracker-date-time.c
index ff64e87..e8279d7 100644
--- a/src/libtracker-common/tracker-date-time.c
+++ b/src/libtracker-common/tracker-date-time.c
@@ -45,8 +45,7 @@ tracker_string_to_date (const gchar *date_string,
                         gint        *offset_p,
                         GError      **error)
 {
-       /* TODO Add more checks and use GError to report invalid input
-        * as this is potential user input.
+       /* TODO Add more checks.
         */
 
        static GRegex *regex = NULL;
@@ -58,7 +57,11 @@ tracker_string_to_date (const gchar *date_string,
        gint offset;
        gboolean timezoned;
 
-       g_return_val_if_fail (date_string, -1);
+       if (!date_string) {
+               g_set_error (error, TRACKER_DATE_ERROR, TRACKER_DATE_ERROR_EMPTY,
+                            "Empty date string");
+               return -1;
+       }
 
        /* We should have a valid iso 8601 date in format
         * YYYY-MM-DDThh:mm:ss with optional TZ
diff --git a/src/libtracker-common/tracker-date-time.h b/src/libtracker-common/tracker-date-time.h
index fee7ba4..78b56eb 100644
--- a/src/libtracker-common/tracker-date-time.h
+++ b/src/libtracker-common/tracker-date-time.h
@@ -32,7 +32,8 @@ G_BEGIN_DECLS
 
 typedef enum  {
        TRACKER_DATE_ERROR_OFFSET,
-       TRACKER_DATE_ERROR_INVALID_ISO8601
+       TRACKER_DATE_ERROR_INVALID_ISO8601,
+       TRACKER_DATE_ERROR_EMPTY
 } TrackerDateError;
 
 #define TRACKER_TYPE_DATE_TIME                 (tracker_date_time_get_type ())