[pygobject] Fix reference sharing of gi sub-modules in Python 2

[Simon Feltman <sfeltman src gnome org>]

commit 7222a37a4b4955fe6c1dcc86e0eb798d653711e8
Author: Simon Feltman <sfeltman src gnome org>
Date:   Wed Jan 15 12:51:57 2014 -0800

    Fix reference sharing of gi sub-modules in Python 2
    
    Ensure we add a new reference to sub-modules added to gi._gi. This may
    have caused GC errors upon exiting the Python process since a reference was
    shared by sys.modules and gi._gi.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=722274

 gi/gimodule.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/gi/gimodule.c b/gi/gimodule.c
index e0d9878..ef3e205 100644
--- a/gi/gimodule.c
+++ b/gi/gimodule.c
@@ -643,6 +643,14 @@ PYGLIB_MODULE_START(_gi, "_gi")
     if (_glib_module == NULL) {
         return PYGLIB_MODULE_ERROR_RETURN;
     }
+    /* In Python 2.x, pyglib_..._module_create returns a borrowed reference and
+     * PyModule_AddObject steals a reference. Ensure we don't share a reference
+     * between sys.modules and gi._gi._glib by incrementing the ref count here.
+     * Note that we don't add this to the PYGLIB_MODULE_START macro because that
+     * would cause a leak for the main module gi._gi */
+    if (PY_MAJOR_VERSION < 3) {
+        Py_INCREF (_glib_module);
+    }
     PyModule_AddObject (module, "_glib", _glib_module);
     PyModule_AddStringConstant(module, "__package__", "gi._gi");
 
@@ -650,6 +658,9 @@ PYGLIB_MODULE_START(_gi, "_gi")
     if (_gobject_module == NULL) {
         return PYGLIB_MODULE_ERROR_RETURN;
     }
+    if (PY_MAJOR_VERSION < 3) {
+        Py_INCREF (_gobject_module);
+    }
     PyModule_AddObject (module, "_gobject", _gobject_module);
     PyModule_AddStringConstant(module, "__package__", "gi._gi");