From f7d9efd98ba97bbe9933db17db1980cd25b2cf48 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Thu, 17 Jan 2013 14:38:28 +1100
Subject: [PATCH] Silence "Access to field 'type' results in a dereference of a
 null pointer" by adding appropriate assertions.

---
 lib/isccfg/include/isccfg/cfg.h | 4 ++++
 lib/isccfg/parser.c             | 7 ++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/isccfg/include/isccfg/cfg.h b/lib/isccfg/include/isccfg/cfg.h
index 0d5e6ea2d8..91ffc34bb5 100644
--- a/lib/isccfg/include/isccfg/cfg.h
+++ b/lib/isccfg/include/isccfg/cfg.h
@@ -395,6 +395,10 @@ cfg_obj_istype(const cfg_obj_t *obj, const cfg_type_t *type);
 void cfg_obj_destroy(cfg_parser_t *pctx, cfg_obj_t **obj);
 /*%<
  * Destroy a configuration object.
+ *
+ * Require:
+ * \li     '*obj' is a valid cfg_obj_t.
+ * \li     'pctx' is a valid cfg_parser_t.
  */
 
 void
diff --git a/lib/isccfg/parser.c b/lib/isccfg/parser.c
index 3d02379447..d6e1643a50 100644
--- a/lib/isccfg/parser.c
+++ b/lib/isccfg/parser.c
@@ -2390,7 +2390,12 @@ cfg_obj_istype(const cfg_obj_t *obj, const cfg_type_t *type) {
  */
 void
 cfg_obj_destroy(cfg_parser_t *pctx, cfg_obj_t **objp) {
-	cfg_obj_t *obj = *objp;
+	cfg_obj_t *obj;
+
+	REQUIRE(objp != NULL && *objp != NULL);
+	REQUIRE(pctx != NULL);
+
+	obj = *objp;
 	obj->type->rep->free(pctx, obj);
 	isc_mem_put(pctx->mctx, obj, sizeof(cfg_obj_t));
 	*objp = NULL;