From c784c67a28f5b92d396eaa9529d57ef91a5cb9ac Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Mon, 2 May 2011 15:59:57 -0400
Subject: [PATCH] [unicode] Make _get_parent() return _nil object instead of
 NULL

---
 src/hb-unicode.cc   | 29 ++++++++++++-----------------
 test/test-unicode.c |  2 +-
 2 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/src/hb-unicode.cc b/src/hb-unicode.cc
index 0486be3..e8eb553 100644
--- a/src/hb-unicode.cc
+++ b/src/hb-unicode.cc
@@ -110,22 +110,18 @@ hb_unicode_funcs_create (hb_unicode_funcs_t *parent)
   if (!(ufuncs = hb_object_create<hb_unicode_funcs_t> ()))
     return &_hb_unicode_funcs_nil;
 
-  if (parent != NULL)
-  {
-    hb_unicode_funcs_make_immutable (parent);
-    ufuncs->parent = hb_unicode_funcs_reference (parent);
+  if (!parent)
+    parent = &_hb_unicode_funcs_nil;
 
-    ufuncs->get = parent->get;
+  hb_unicode_funcs_make_immutable (parent);
+  ufuncs->parent = hb_unicode_funcs_reference (parent);
 
-    /* We can safely copy user_data from parent since we hold a reference
-     * onto it and it's immutable.  We should not copy the destroy notifiers
-     * though. */
-    ufuncs->user_data = parent->user_data;
-  }
-  else
-  {
-    ufuncs->get = _hb_unicode_funcs_nil.get;
-  }
+  ufuncs->get = parent->get;
+
+  /* We can safely copy user_data from parent since we hold a reference
+   * onto it and it's immutable.  We should not copy the destroy notifiers
+   * though. */
+  ufuncs->user_data = parent->user_data;
 
   return ufuncs;
 }
@@ -149,8 +145,7 @@ hb_unicode_funcs_destroy (hb_unicode_funcs_t *ufuncs)
   DESTROY (script);
 #undef DESTROY
 
-  if (ufuncs->parent != NULL)
-    hb_unicode_funcs_destroy (ufuncs->parent);
+  hb_unicode_funcs_destroy (ufuncs->parent);
 
   free (ufuncs);
 }
@@ -190,7 +185,7 @@ hb_unicode_funcs_is_immutable (hb_unicode_funcs_t *ufuncs)
 hb_unicode_funcs_t *
 hb_unicode_funcs_get_parent (hb_unicode_funcs_t *ufuncs)
 {
-  return ufuncs->parent;
+  return ufuncs->parent ? ufuncs->parent : &_hb_unicode_funcs_nil;
 }
 
 
diff --git a/test/test-unicode.c b/test/test-unicode.c
index 96d6806..cc95a9f 100644
--- a/test/test-unicode.c
+++ b/test/test-unicode.c
@@ -67,7 +67,7 @@ simple_get_script (hb_unicode_funcs_t *ufuncs,
 {
   data_t *data = (data_t *) user_data;
 
-  g_assert (hb_unicode_funcs_get_parent (ufuncs) == NULL);
+  g_assert (hb_unicode_funcs_get_parent (ufuncs) != NULL);
   g_assert (data->value == MAGIC0);
   g_assert (data->freed == FALSE);
 
-- 
2.7.4