diff --git a/src/builtins/sfns.c b/src/builtins/sfns.c index 952b27f9..fc1bf449 100644 --- a/src/builtins/sfns.c +++ b/src/builtins/sfns.c @@ -889,7 +889,10 @@ B join_c1(B t, B x) { } } B join_c2(B t, B w, B x) { - if (isAtm(w)) w = m_unit(w); + if (isAtm(w)) { + if (isAtm(x)) return pair_c2(t, w, x); + w = m_unit(w); + } ur wr = RNK(w); if (isAtm(x)) { if (wr==1 && inplace_add(w, x)) return w;