util.dataforms: Fix verfication for booleans

diff --git a/util/dataforms.lua b/util/dataforms.lua
index b69df819709321ca8cfcdf6b859c7f83af7e9515..d4a1865c806aca39aa2a8dfafea35e440065b747 100644 (file)
--- a/util/dataforms.lua
+++ b/util/dataforms.lua
@@ -252,7 +252,7 @@ field_readers["boolean"] =
 field_verifiers["boolean"] =
        function (data, field_tag, required)
                data = field_readers["text-single"](field_tag);
-               if #data == 0 and required then
+               if ((not data) or (#data == 0)) and required then
                        return "Required value missing";
                end
                if data ~= "1" and data ~= "true" and data ~= "0" and data ~= "false" then