dbus_g_proxy_end_call_internal: zero out all "out" arguments on entrywip-garbage-out-values-7206-a

FIXME: Code written for this version might crash badly on older dbus-glib;
perhaps it'd be better to write invalid pointers through?

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=7206

1 files changed, 36 insertions, 5 deletions

diff --git a/dbus/dbus-gproxy.c b/dbus/dbus-gproxy.c
index c683b44..566cb33 100644
--- a/dbus/dbus-gproxy.c
+++ b/dbus/dbus-gproxy.c
@@ -2341,7 +2341,7 @@ dbus_g_proxy_end_call_internal (DBusGProxy        *proxy,
   DBusMessage *reply;
   DBusMessageIter msgiter;
   DBusError derror;
-  va_list args_unwind;
+  va_list args_copy;
   guint over;
   int n_retvals_processed;
   gboolean ret;
@@ -2354,8 +2354,39 @@ dbus_g_proxy_end_call_internal (DBusGProxy        *proxy,
   n_retvals_processed = 0;
   over = 0;
 
+  G_VA_COPY (args_copy, args);
+
+  for (valtype = first_arg_type;
+      valtype != G_TYPE_INVALID;
+      valtype = va_arg (args_copy, GType))
+    {
+      gpointer return_storage = va_arg (args_copy, gpointer);
+
+      if (return_storage == NULL)
+        continue;
+
+      if (g_type_is_a (valtype, G_TYPE_VALUE))
+        {
+          /* grumble grumble different calling conventions grumble */
+          GValue *value = return_storage;
+
+          memset (value, '\0', sizeof (GValue));
+        }
+      else
+        {
+          GValue value = { 0 };
+
+          g_value_init (&value, valtype);
+
+          if (!_dbus_gvalue_store (&value, return_storage))
+            g_assert_not_reached ();
+        }
+    }
+
+  va_end (args_copy);
+
   /* Keep around a copy of output arguments so we can free on error. */
-  G_VA_COPY(args_unwind, args);
+  G_VA_COPY(args_copy, args);
 
   pending = g_hash_table_lookup (priv->pending_calls, GUINT_TO_POINTER (call_id));
   
@@ -2474,7 +2505,7 @@ dbus_g_proxy_end_call_internal (DBusGProxy        *proxy,
 
           g_value_init (&value, valtype);
 
-	  retval = va_arg (args_unwind, gpointer);
+	  retval = va_arg (args_copy, gpointer);
           if (retval == NULL)
             {
               i--;
@@ -2484,10 +2515,10 @@ dbus_g_proxy_end_call_internal (DBusGProxy        *proxy,
           _dbus_gvalue_take (&value, retval);
           g_value_unset (&value);
 
-          valtype = va_arg (args_unwind, GType);
+          valtype = va_arg (args_copy, GType);
 	}
     }
-  va_end (args_unwind);
+  va_end (args_copy);
   va_end (args);
 
   g_hash_table_remove (priv->pending_calls, GUINT_TO_POINTER (call_id));