[Xfce4-commits] <xfce4-weather-plugin:master> Set data to NULL after free, but report double-free.

[Harald Judt]

Updating branch refs/heads/master
         to a7eafaaac94476c0a6143ded7883b5bf5b82d9f3 (commit)
       from 576f9d15c39e913724a8cf17dd3763e3e4d17cae (commit)

commit a7eafaaac94476c0a6143ded7883b5bf5b82d9f3
Author: Harald Judt <h.judt at gmx.at>
Date:   Wed Jul 25 08:00:54 2012 +0200

    Set data to NULL after free, but report double-free.
    
    To prevent undefined behaviour, set structs to NULL after
    freeing them, but also put assertions in to report double-free
    attempts.

 panel-plugin/weather-parsers.c |   12 ++++++++++++
 panel-plugin/weather.c         |    2 ++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/panel-plugin/weather-parsers.c b/panel-plugin/weather-parsers.c
index c0326fb..6442d42 100644
--- a/panel-plugin/weather-parsers.c
+++ b/panel-plugin/weather-parsers.c
@@ -239,6 +239,9 @@ void parse_location (xmlNode * cur_node, xml_location *loc)
 
 static void xml_location_free(xml_location *loc)
 {
+	g_assert(loc != NULL);
+	if (G_UNLIKELY(loc == NULL))
+		return;
 	g_free(loc->altitude);
 	g_free(loc->latitude);
 	g_free(loc->longitude);
@@ -261,21 +264,30 @@ static void xml_location_free(xml_location *loc)
 	g_free(loc->precipitation_unit);
 	g_free(loc->symbol);
 	g_slice_free (xml_location, loc);
+	loc = NULL;
 }
 
 void xml_time_free(xml_time *timeslice)
 {
+  g_assert(timeslice != NULL);
+  if (G_UNLIKELY(timeslice == NULL))
+    return;
   xml_location_free(timeslice->location);
   g_slice_free (xml_time, timeslice);
+  timeslice = NULL;
 }
 
 void xml_weather_free (xml_weather *data)
 {
   guint i;
 
+  g_assert(data != NULL);
+  if (G_UNLIKELY(data == NULL))
+    return;
   for (i = 0; i < data->num_timeslices; i++) {
     xml_time_free(data->timeslice[i]);
   }
   xml_time_free(data->current_conditions);
   g_slice_free (xml_weather, data);
+  data = NULL;
 }
diff --git a/panel-plugin/weather.c b/panel-plugin/weather.c
index c95cccb..5eb81f3 100644
--- a/panel-plugin/weather.c
+++ b/panel-plugin/weather.c
@@ -1005,6 +1005,7 @@ static void
 xfceweather_free (XfcePanelPlugin  *plugin,
                   xfceweather_data *data)
 {
+  g_assert(data != NULL);
   weather_http_cleanup_qeue ();
 
   if (data->weatherdata)
@@ -1035,6 +1036,7 @@ xfceweather_free (XfcePanelPlugin  *plugin,
   g_array_free (data->labels, TRUE);
 
   g_slice_free (xfceweather_data, data);
+  data = NULL;
 }