[pygobject] Fix memory handling of caller-allocated boxed types

[Martin Pitt <martinpitt src gnome org>]

commit 64bcca2d39fed1734ad1abbe291406387e901f5c
Author: Martin Pitt <martinpitt gnome org>
Date:   Thu Feb 28 10:48:18 2013 +0100

    Fix memory handling of caller-allocated boxed types
    
    _pygi_marshal_to_py_interface_struct() and other places treat subtypes of
    G_TYPE_BOXED as boxed values and wrap them with _pygi_boxed_new(). Fix
    _caller_alloc() and _cleanup_caller_allocates() to consider G_TYPE_BOXED
    subtypes as well and use the slice allocator instead of malloc()'ing a struct.
    This avoids trying to free an malloc'ed struct with g_slice_free() and properly
    cleans up the boxed values.
    
    The leak was produced with:
    
    G_SLICE=debug-blocks PYTHONPATH=. valgrind --tool=memcheck --leak-check=full --show-possibly-lost=no \
      python3 -c 'from gi.repository import Gtk; b=Gtk.TextBuffer(); (s,e) = b.get_bounds()'

 gi/pygi-invoke.c          |    2 +-
 gi/pygi-marshal-cleanup.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gi/pygi-invoke.c b/gi/pygi-invoke.c
index 96ffde3..0cbb9ca 100644
--- a/gi/pygi-invoke.c
+++ b/gi/pygi-invoke.c
@@ -366,7 +366,7 @@ static gboolean _caller_alloc (PyGIInvokeState *state,
 
         state->out_args[out_count].v_pointer = NULL;
         state->args[arg_count] = &state->out_args[out_count];
-        if (iface_cache->g_type == G_TYPE_BOXED) {
+        if (g_type_is_a (iface_cache->g_type, G_TYPE_BOXED)) {
             state->args[arg_count]->v_pointer =
                 _pygi_boxed_alloc (iface_cache->interface_info, NULL);
         } else if (iface_cache->g_type == G_TYPE_VALUE) {
diff --git a/gi/pygi-marshal-cleanup.c b/gi/pygi-marshal-cleanup.c
index 50f593d..77fbf08 100644
--- a/gi/pygi-marshal-cleanup.c
+++ b/gi/pygi-marshal-cleanup.c
@@ -29,7 +29,7 @@ _cleanup_caller_allocates (PyGIInvokeState    *state,
 {
     PyGIInterfaceCache *iface_cache = (PyGIInterfaceCache *)cache;
 
-    if (iface_cache->g_type == G_TYPE_BOXED) {
+    if (g_type_is_a (iface_cache->g_type, G_TYPE_BOXED)) {
         gsize size;
         if (was_processed)
             return; /* will be cleaned up at deallocation */