lib-var-expand: Ensure provider returns either error or value

diff --git a/src/lib-var-expand/var-expand.c b/src/lib-var-expand/var-expand.c
index 960412045b888f7cae988ece394ec4e49fffd175..d1e3e20525f54c022199accc79b6c43864110e06 100644 (file)
--- a/src/lib-var-expand/var-expand.c
+++ b/src/lib-var-expand/var-expand.c
@@ -392,6 +392,8 @@ static int call_value_provider(const struct var_expand_state *state,
                ret = -1;
        }
 
+       i_assert(*value_r != NULL || ret == -1);
+
        return ret;
 }