3 files changed, 17 insertions, 14 deletions

diff --git a/source4/lib/ldb/common/ldb_alloc.c b/source4/lib/ldb/common/ldb_alloc.c
index 6abd6fa8c3..0053c5e73f 100644
--- a/source4/lib/ldb/common/ldb_alloc.c
+++ b/source4/lib/ldb/common/ldb_alloc.c
@@ -39,7 +39,7 @@
   this allows the user to choose their own allocation function
 */
 int ldb_set_alloc(struct ldb_context *ldb,
-		  void *(*alloc)(void *context, void *ptr, size_t size),
+		  void *(*alloc)(const void *context, void *ptr, size_t size),
 		  void *context)
 {
 	ldb->alloc_ops.alloc = alloc;
@@ -50,7 +50,7 @@ int ldb_set_alloc(struct ldb_context *ldb,
 /*
   this is the default memory allocation function
 */
-static void *ldb_default_alloc(void *context, void *ptr, size_t size)
+static void *ldb_default_alloc(const void *context, void *ptr, size_t size)
 {
 	/* by setting LDB_ALLOC_OFS to non-zero the test suite can
 	   catch any places where we incorrectly use the libc alloc
diff --git a/source4/lib/ldb/include/ldb.h b/source4/lib/ldb/include/ldb.h
index 241f186991..4b1401f673 100644
--- a/source4/lib/ldb/include/ldb.h
+++ b/source4/lib/ldb/include/ldb.h
@@ -145,7 +145,7 @@ struct ldb_backend_ops {
   for pool allocators
 */
 struct ldb_alloc_ops {
-	void *(*alloc)(void *context, void *ptr, size_t size);
+	void *(*alloc)(const void *context, void *ptr, size_t size);
 	void *context;
 };
 
@@ -320,7 +320,7 @@ const char *ldb_msg_find_string(const struct ldb_message *msg,
   which often take a context argument
 */
 int ldb_set_alloc(struct ldb_context *ldb,
-		  void *(*alloc)(void *context, void *ptr, size_t size),
+		  void *(*alloc)(const void *context, void *ptr, size_t size),
 		  void *context);
 
 /*
diff --git a/source4/lib/talloc.c b/source4/lib/talloc.c
index fc65546063..5c1f3e7dcd 100644
--- a/source4/lib/talloc.c
+++ b/source4/lib/talloc.c
@@ -273,6 +273,10 @@ int talloc_unlink(const void *context, void *ptr)
 	struct talloc_chunk *tc_p, *new_p;
 	void *new_parent;
 
+	if (context == NULL) {
+		context = null_context;
+	}
+
 	if (talloc_unreference(context, ptr) == 0) {
 		return 0;
 	}
@@ -561,6 +565,10 @@ void *talloc_steal(const void *new_ctx, const void *ptr)
 		return NULL;
 	}
 
+	if (new_ctx == NULL) {
+		new_ctx = null_context;
+	}
+
 	tc = talloc_chunk_from_ptr(ptr);
 
 	if (new_ctx == NULL) {
@@ -948,16 +956,11 @@ void *talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned
 }
 
 /*
-  a alloc function for ldb that uses talloc
+  a function version of talloc_realloc(), so it can be passed as a function pointer
+  to libraries that want a realloc function (a realloc function encapsulates
+  all the basic capabilities of an allocation library, which is why this is useful)
 */
-void *talloc_ldb_alloc(void *context, void *ptr, size_t size)
+void *talloc_realloc_fn(const void *context, void *ptr, size_t size)
 {
-	if (ptr == NULL) {
-		return talloc(context, size);
-	}
-	if (size == 0) {
-		talloc_free(ptr);
-		return NULL;
-	}
-	return talloc_realloc(context, ptr, size);
+	return _talloc_realloc(context, ptr, size, NULL);
 }