Fix Py list length check in cpy_build_meta()

diff --git a/src/pyvalues.c b/src/pyvalues.c
index 4f5c4ce..137d5eb 100644 (file)
--- a/src/pyvalues.c
+++ b/src/pyvalues.c
@@ -427,10 +427,9 @@ static meta_data_t *cpy_build_meta(PyObject *meta) {
                cpy_log_exception("building meta data");
                return NULL;
        }
-
        s = PyList_Size(l);
-       if (s < 0)
-               return NULL;
+    if (s <= 0)
+        return NULL;
 
        m = meta_data_create();
        for (i = 0; i < s; ++i) {