store: Return NULL if an attribute was not found.

diff --git a/src/core/store_expr.c b/src/core/store_expr.c
index 0a8757f0911568b5b9b2cf8c66ad1fcc0ade62cd..ed0589bc28d1a37c32c6ea93400331410b01c532 100644 (file)
--- a/src/core/store_expr.c
+++ b/src/core/store_expr.c
@@ -172,8 +172,16 @@ sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
                return sdb_data_copy(res, &expr->data);
        else if (expr->type == FIELD_VALUE)
                return sdb_store_get_field(obj, (int)expr->data.data.integer, res);
-       else if (expr->type == ATTR_VALUE)
-               return sdb_store_get_attr(obj, expr->data.data.string, res, filter);
+       else if (expr->type == ATTR_VALUE) {
+               status = sdb_store_get_attr(obj, expr->data.data.string, res, filter);
+               if ((status < 0) && obj) {
+                       /* attribute does not exist => NULL */
+                       status = 0;
+                       res->type = SDB_TYPE_STRING;
+                       res->data.string = NULL;
+               }
+               return status;
+       }
 
        if (sdb_store_expr_eval(expr->left, obj, &v1, filter))
                return -1;