From: Vladimír Čunát <vladimir.cunat@nic.cz>
Date: Thu, 24 Nov 2016 10:28:00 +0000 (+0100)
Subject: lua cache.count(): return nil on error
X-Git-Tag: v1.2.0-rc1~73^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=345c5fa631d5638ea0df4b18bc9438fe4ba6f5ac;p=thirdparty%2Fknot-resolver.git

lua cache.count(): return nil on error

... and avoid returning a negative number.
---

diff --git a/daemon/README.rst b/daemon/README.rst
index b3958eecc..fbad4f787 100644
--- a/daemon/README.rst
+++ b/daemon/README.rst
@@ -768,7 +768,7 @@ daemons or manipulated from other processes, making for example synchronised loa
 
 .. function:: cache.count()
 
-   :return: Number of entries in the cache.
+   :return: Number of entries in the cache or nil on error.
 
 .. function:: cache.close()
 
diff --git a/daemon/bindings.c b/daemon/bindings.c
index 408603a05..75cd16c8b 100644
--- a/daemon/bindings.c
+++ b/daemon/bindings.c
@@ -430,10 +430,11 @@ static int cache_count(lua_State *L)
 	struct engine *engine = engine_luaget(L);
 	const struct kr_cdb_api *api = engine->resolver.cache.api;
 
-	/* First key is a version counter, omit it. */
 	struct kr_cache *cache = &engine->resolver.cache;
-	if (kr_cache_is_open(cache)) {
-		lua_pushinteger(L, api->count(cache->db) - 1);
+	int count = api->count(cache->db);
+	if (kr_cache_is_open(cache) && count >= 0) {
+		/* First key is a version counter, omit it if nonempty. */
+		lua_pushinteger(L, count ? count - 1 : 0);
 		return 1;
 	}
 	return 0;