lua: make the map command check its arguments

Fixes #147.

diff --git a/daemon/engine.c b/daemon/engine.c
index 9b53b1bc981918befdd530f8e8eb8cd164c46782..21cf159040ea8221db9fca3d570412da704795d2 100644 (file)
--- a/daemon/engine.c
+++ b/daemon/engine.c
@@ -376,6 +376,11 @@ static int l_tojson(lua_State *L)
 
 static int l_map(lua_State *L)
 {
+       if (lua_gettop(L) != 1 || !lua_isstring(L, 1)) {
+               lua_pushliteral(L, "map('string with a lua expression')");
+               lua_error(L);
+       }
+
        struct engine *engine = engine_luaget(L);
        const char *cmd = lua_tostring(L, 1);
        uint32_t len = strlen(cmd);