telepathy-glib: TpProtocol: fix some suspicious memory management

[Simon McVittie]

Module: telepathy-glib
Branch: master
Commit: 58557fc633c44c261d5e1a8c85438fa12bdf72e6
URL:    http://cgit.freedesktop.org/telepathy/telepathy-glib/commit/?id=58557fc633c44c261d5e1a8c85438fa12bdf72e6

Author: Simon McVittie <simon.mcvittie at collabora.co.uk>
Date:   Thu Jan 30 20:04:08 2014 +0000

TpProtocol: fix some suspicious memory management

It works fine as long as a preallocated GArray doesn't move its memory
buffer for no reason, but it's good to be obviously correct. Spotted while
working on the previous commit.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=71093
Reviewed-by: Guillaume Desmottes <guillaume.desmottes at collabora.co.uk>

---

 telepathy-glib/protocol.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/telepathy-glib/protocol.c b/telepathy-glib/protocol.c
index ee9b7e2..3c7ed99 100644
--- a/telepathy-glib/protocol.c
+++ b/telepathy-glib/protocol.c
@@ -192,15 +192,15 @@ tp_protocol_params_from_param_specs (const GPtrArray *parameters,
     {
       GValue structure = { 0 };
       GValue *tmp;
-      /* Points to the zeroed entry just after the end of the array
-       * - but we're about to extend the array to make it valid */
-      TpConnectionManagerParam *param = &g_array_index (output,
-          TpConnectionManagerParam, output->len);
+      TpConnectionManagerParam *param;
 
       g_value_init (&structure, TP_STRUCT_TYPE_PARAM_SPEC);
       g_value_set_static_boxed (&structure, g_ptr_array_index (parameters, i));
 
       g_array_set_size (output, output->len + 1);
+      /* point to the new last item */
+      param = &g_array_index (output, TpConnectionManagerParam,
+          output->len - 1);
 
       if (!dbus_g_type_struct_get (&structure,
             0, &param->name,