From d844c4d276b78fd5100a026ac612e26f3f085617 Mon Sep 17 00:00:00 2001
From: Ulf Norell <ulf.norell@gmail.com>
Date: Thu, 12 Dec 2019 08:50:17 +0100
Subject: [PATCH] Fix missing type annotation in list comprehension body

---
 src/aeso_ast_infer_types.erl     | 2 +-
 test/aeso_compiler_tests.erl     | 1 +
 test/contracts/lc_record_bug.aes | 4 ++++
 3 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 test/contracts/lc_record_bug.aes

diff --git a/src/aeso_ast_infer_types.erl b/src/aeso_ast_infer_types.erl
index fcca92f..5afe2e3 100644
--- a/src/aeso_ast_infer_types.erl
+++ b/src/aeso_ast_infer_types.erl
@@ -1138,7 +1138,7 @@ infer_expr(Env, {list, As, Elems}) ->
     NewElems = [check_expr(Env, X, ElemType) || X <- Elems],
     {typed, As, {list, As, NewElems}, {app_t, As, {id, As, "list"}, [ElemType]}};
 infer_expr(Env, {list_comp, As, Yield, []}) ->
-    {typed, _, TypedYield, Type} = infer_expr(Env, Yield),
+    {typed, _, _, Type} = TypedYield = infer_expr(Env, Yield),
     {typed, As, {list_comp, As, TypedYield, []}, {app_t, As, {id, As, "list"}, [Type]}};
 infer_expr(Env, {list_comp, As, Yield, [{comprehension_bind, Arg, BExpr}|Rest]}) ->
     BindVarType = fresh_uvar(As),
diff --git a/test/aeso_compiler_tests.erl b/test/aeso_compiler_tests.erl
index b4d400e..3ddca8c 100644
--- a/test/aeso_compiler_tests.erl
+++ b/test/aeso_compiler_tests.erl
@@ -138,6 +138,7 @@ compilable_contracts() ->
      "test",
      "builtin_bug",
      "builtin_map_get_bug",
+     "lc_record_bug",
      "nodeadcode",
      "deadcode",
      "variant_types",
diff --git a/test/contracts/lc_record_bug.aes b/test/contracts/lc_record_bug.aes
new file mode 100644
index 0000000..dcce24d
--- /dev/null
+++ b/test/contracts/lc_record_bug.aes
@@ -0,0 +1,4 @@
+contract Foo =
+  record r = {x : int}
+  // Crashed in the backend due to missing type annotation on the lc body.
+  entrypoint lc(xs) = [ {x = x} | x <- xs ]