diff options
| -rw-r--r-- | src/libexpr/primops.cc | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index db27b716b023..f8f893d69683 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -950,15 +950,22 @@ static void prim_filter(EvalState & state, Value * * args, Value & v) Value * vs[args[1]->list.length]; unsigned int k = 0; + bool same = true; for (unsigned int n = 0; n < args[1]->list.length; ++n) { Value res; state.callFunction(*args[0], *args[1]->list.elems[n], res); if (state.forceBool(res)) vs[k++] = args[1]->list.elems[n]; + else + same = false; } - state.mkList(v, k); - for (unsigned int n = 0; n < k; ++n) v.list.elems[n] = vs[n]; + if (same) + v = *args[1]; + else { + state.mkList(v, k); + for (unsigned int n = 0; n < k; ++n) v.list.elems[n] = vs[n]; + } } |