libexpr: add expr memory management

with the prepatory work done this mostly means turning plain pointers
into unique_ptrs, with all the associated churn that necessitates. we
might want to change some of these to box_ptrs at some point as well,
but that would be a semantic change that isn't fully appropriate yet.

Change-Id: I0c238c118617420650432f4ed45569baa3e3f413

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 720ab1a3f..4b7e61dfe 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -2817,7 +2817,7 @@ static void prim_functionArgs(EvalState & state, const PosIdx pos, Value * * arg
     auto attrs = state.buildBindings(args[0]->lambda.fun->formals->formals.size());
     for (auto & i : args[0]->lambda.fun->formals->formals)
         // !!! should optimise booleans (allocate only once)
-        attrs.alloc(i.name, i.pos).mkBool(i.def);
+        attrs.alloc(i.name, i.pos).mkBool(i.def != nullptr);
     v.mkAttrs(attrs);
 }