From 226556bdd6f61b6712d82782ab688719fbfafdfa Mon Sep 17 00:00:00 2001
From: microproofs <kwhitemsg@gmail.com>
Date: Fri, 23 Jun 2023 14:30:29 -0400
Subject: [PATCH] fix: builtins using the incorrect data to type conversion
 when used as a function param.

---
 CHANGELOG.md                               | 1 +
 crates/aiken-lang/src/gen_uplc.rs          | 9 +++++++--
 examples/acceptance_tests/084/lib/tests.ak | 7 +++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6cc249d2..7541f296 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@
 - **aiken-lang**: Fix for tuple clause not consuming the next case causing
   incomplete contracts. Now tuple clause will always consume the next case
   unless it is the final clause
+  - **aiken-lang**: Fix for builtins using the incorrect data to type conversion when used as a function param.
 
 ## v1.0.10-alpha - 2023-06-13
 
diff --git a/crates/aiken-lang/src/gen_uplc.rs b/crates/aiken-lang/src/gen_uplc.rs
index c6c1a860..68e0709f 100644
--- a/crates/aiken-lang/src/gen_uplc.rs
+++ b/crates/aiken-lang/src/gen_uplc.rs
@@ -4168,6 +4168,11 @@ impl<'a> CodeGenerator<'a> {
                     arg_vec.push(arg_stack.pop().unwrap());
                 }
 
+                let tipo = match tipo.as_ref() {
+                    Type::Fn { ret, .. } => ret,
+                    _ => &tipo,
+                };
+
                 let term = match &func {
                     DefaultFunction::IfThenElse
                     | DefaultFunction::ChooseUnit
@@ -4181,11 +4186,11 @@ impl<'a> CodeGenerator<'a> {
                     DefaultFunction::FstPair
                     | DefaultFunction::SndPair
                     | DefaultFunction::HeadList => {
-                        builder::undata_builtin(&func, count, &tipo, arg_vec)
+                        builder::undata_builtin(&func, count, tipo, arg_vec)
                     }
 
                     DefaultFunction::MkCons | DefaultFunction::MkPairData => {
-                        builder::to_data_builtin(&func, count, &tipo, arg_vec)
+                        builder::to_data_builtin(&func, count, tipo, arg_vec)
                     }
                     _ => {
                         let mut term: Term<Name> = func.into();
diff --git a/examples/acceptance_tests/084/lib/tests.ak b/examples/acceptance_tests/084/lib/tests.ak
index 962b5a6a..e9db5434 100644
--- a/examples/acceptance_tests/084/lib/tests.ak
+++ b/examples/acceptance_tests/084/lib/tests.ak
@@ -1,3 +1,5 @@
+use aiken/builtin.{snd_pair}
+use aiken/cbor
 use aiken/list
 
 test tuple_when() {
@@ -20,3 +22,8 @@ test tuple_when() {
     )
   list.length(filtered) > 0
 }
+
+test t() {
+  trace cbor.diagnostic(list.map([(#"", 20)], snd_pair))
+  True
+}