Merge lp://qastaging/~charlesk/libunity/lp-981309 into lp://qastaging/libunity

Plug a GHashTable leak in unity-launcher's serialize()

I'm still getting up to speed with Vala and am not sure whether or not this patch is The Right Fix.

Looking at the C code is useful: it looks like Vala's being confused by the implicit conversion of collect_launcher_entry_properties()'s return value from a HashTable to a Variant (ie, Variant foo = collect()).

If we add a HashTable local (ie, HashTable foo = collect(); Variant bar = foo;) then vala's C code correctly adds a call to g_hash_table_unref().

Here's the diff in valac's C code generated from that:

--- unity-launcher.c.bak 2012-04-13 20:04:07.813563352 -0500
+++ unity-launcher.c 2012-04-13 20:11:06.453573302 -0500
@@ -603,6 +603,7 @@
  UnityLauncherEntry * self;
  GVariant* result = NULL;
  GHashTable* _tmp0_ = NULL;
+ GHashTable* hash;
  GVariant* _tmp5_;
  GVariant* props;
  const gchar* _tmp6_;
@@ -619,7 +620,8 @@
  GVariant* _tmp15_;
  self = (UnityLauncherEntry*) base;
  _tmp0_ = unity_collect_launcher_entry_properties (self);
- _tmp5_ = _variant_new1 (_tmp0_);
+ hash = _tmp0_;
+ _tmp5_ = _variant_new1 (hash);
  props = _tmp5_;
  _tmp6_ = self->priv->_app_uri;
  _tmp7_ = g_variant_new_string (_tmp6_);
@@ -639,6 +641,7 @@
  result = _tmp15_;
  _g_variant_unref0 (_app_uri);
  _g_variant_unref0 (props);
+ _g_hash_table_unref0 (hash);
  return result;
 }