[glib: 16/19] gvariant: Fix pointers being dereferenced despite NULL checks

[Philip Withnall <pwithnall src gnome org>]

commit 7f6ce4d8d234996b523b71abef139f1c80c88254
Author: Egor Bychin <e bychin drweb com>
Date:   Mon Oct 11 14:24:12 2021 +0300

    gvariant: Fix pointers being dereferenced despite NULL checks

 glib/gvariant.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)
---
diff --git a/glib/gvariant.c b/glib/gvariant.c
index 4a9704c19..5fa6a8268 100644
--- a/glib/gvariant.c
+++ b/glib/gvariant.c
@@ -3196,8 +3196,7 @@ struct heap_builder
 #define GVSB_MAGIC               ((gsize) 1033660112u)
 #define GVSB_MAGIC_PARTIAL       ((gsize) 2942751021u)
 #define GVHB_MAGIC               ((gsize) 3087242682u)
-#define is_valid_builder(b)      (b != NULL && \
-                                  GVSB(b)->magic == GVSB_MAGIC)
+#define is_valid_builder(b)      (GVSB(b)->magic == GVSB_MAGIC)
 #define is_valid_heap_builder(b) (GVHB(b)->magic == GVHB_MAGIC)
 
 /* Just to make sure that by adding a union to GVariantBuilder, we
@@ -3207,7 +3206,9 @@ G_STATIC_ASSERT (sizeof (GVariantBuilder) == sizeof (gsize[16]));
 static gboolean
 ensure_valid_builder (GVariantBuilder *builder)
 {
-  if (is_valid_builder (builder))
+  if (builder == NULL)
+    return FALSE;
+  else if (is_valid_builder (builder))
     return TRUE;
   if (builder->u.s.partial_magic == GVSB_MAGIC_PARTIAL)
     {
@@ -3853,8 +3854,7 @@ struct heap_dict
 #define GVSD_MAGIC              ((gsize) 2579507750u)
 #define GVSD_MAGIC_PARTIAL      ((gsize) 3488698669u)
 #define GVHD_MAGIC              ((gsize) 2450270775u)
-#define is_valid_dict(d)        (d != NULL && \
-                                 GVSD(d)->magic == GVSD_MAGIC)
+#define is_valid_dict(d)        (GVSD(d)->magic == GVSD_MAGIC)
 #define is_valid_heap_dict(d)   (GVHD(d)->magic == GVHD_MAGIC)
 
 /* Just to make sure that by adding a union to GVariantDict, we didn't
@@ -3864,7 +3864,9 @@ G_STATIC_ASSERT (sizeof (GVariantDict) == sizeof (gsize[16]));
 static gboolean
 ensure_valid_dict (GVariantDict *dict)
 {
-  if (is_valid_dict (dict))
+  if (dict == NULL)
+    return FALSE;
+  else if (is_valid_dict (dict))
     return TRUE;
   if (dict->u.s.partial_magic == GVSD_MAGIC_PARTIAL)
     {