s4-ldb: fixed show_deleted module not to corrupt parse trees

The show_deleted module was using a static private ptr in the module
to hold a parse tree to save on parsing. The code caused this
static ptr to change with each search, which caused incorrect
searches and numerous valgrind errors.

This patch replaces it with a hand-built parse tree.

1 files changed, 26 insertions, 23 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/show_deleted.c b/source4/dsdb/samdb/ldb_modules/show_deleted.c
index 557e36f0bda..11503e6d3bb 100644
--- a/source4/dsdb/samdb/ldb_modules/show_deleted.c
+++ b/source4/dsdb/samdb/ldb_modules/show_deleted.c
@@ -40,7 +40,6 @@ static int show_deleted_search(struct ldb_module *module, struct ldb_request *re
 	struct ldb_control *control;
 	struct ldb_control **saved_controls;
 	struct ldb_request *down_req;
-	struct ldb_parse_tree *nodeleted_tree;
 	struct ldb_parse_tree *new_tree = req->op.search.tree;
 	int ret;
 
@@ -50,19 +49,33 @@ static int show_deleted_search(struct ldb_module *module, struct ldb_request *re
 	control = ldb_request_get_control(req, LDB_CONTROL_SHOW_DELETED_OID);
 
 	if (! control) {
-		nodeleted_tree = talloc_get_type(ldb_module_get_private(module), 
-						 struct ldb_parse_tree);
-		if (nodeleted_tree) {
-			new_tree = talloc(req, struct ldb_parse_tree);
-			if (!new_tree) {
-				ldb_oom(ldb);
-				return LDB_ERR_OPERATIONS_ERROR;
-			}
-			*new_tree = *nodeleted_tree;
-			/* Replace dummy part of 'and' with the old, tree,
-			   without a parse step */
-			new_tree->u.list.elements[0] = req->op.search.tree;
+		/* FIXME: we could use a constant tree here once we
+		   are sure that no ldb modules modify trees
+		   in-situ */
+		new_tree = talloc(req, struct ldb_parse_tree);
+		if (!new_tree) {
+			ldb_oom(ldb);
+			return LDB_ERR_OPERATIONS_ERROR;
 		}
+		new_tree->operation = LDB_OP_AND;
+		new_tree->u.list.num_elements = 2;
+		new_tree->u.list.elements = talloc_array(new_tree, struct ldb_parse_tree *, 2);
+		if (!new_tree->u.list.elements) {
+			ldb_oom(ldb);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		new_tree->u.list.elements[0] = talloc(new_tree->u.list.elements, struct ldb_parse_tree);
+		new_tree->u.list.elements[0]->operation = LDB_OP_NOT;
+		new_tree->u.list.elements[0]->u.isnot.child =
+			talloc(new_tree->u.list.elements, struct ldb_parse_tree);
+		if (!new_tree->u.list.elements[0]->u.isnot.child) {
+			ldb_oom(ldb);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		new_tree->u.list.elements[0]->u.isnot.child->operation = LDB_OP_EQUALITY;
+		new_tree->u.list.elements[0]->u.isnot.child->u.equality.attr = "isDeleted";
+		new_tree->u.list.elements[0]->u.isnot.child->u.equality.value = data_blob_string_const("TRUE");
+		new_tree->u.list.elements[1] = req->op.search.tree;
 	}
 	
 	ret = ldb_build_search_req_ex(&down_req, ldb, req,
@@ -89,20 +102,10 @@ static int show_deleted_search(struct ldb_module *module, struct ldb_request *re
 static int show_deleted_init(struct ldb_module *module)
 {
 	struct ldb_context *ldb;
-	struct ldb_parse_tree *nodeleted_tree;
 	int ret;
 
 	ldb = ldb_module_get_ctx(module);
 
-	nodeleted_tree = ldb_parse_tree(module, "(&(replace=me)(!(isDeleted=TRUE)))");
-	if (!nodeleted_tree) {
-		ldb_debug(ldb, LDB_DEBUG_ERROR,
-			"show_deleted: Unable to parse isDeleted master expression!\n");
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	ldb_module_set_private(module, nodeleted_tree);
-
 	ret = ldb_mod_register_control(module, LDB_CONTROL_SHOW_DELETED_OID);
 	if (ret != LDB_SUCCESS) {
 		ldb_debug(ldb, LDB_DEBUG_ERROR,