From daf9d219d3d224e2da3f3e02e674f02899dfb9f9 Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Mon, 7 Oct 2019 14:25:45 -0700
Subject: [PATCH] fix: must reset assignments before each iteration

Reason: the join points cached values are incorrect since they were
computed using the previous values for `funVals`.
---
 library/Init/Lean/Compiler/IR/UnreachBranches.lean | 1 +
 1 file changed, 1 insertion(+)

diff --git a/library/Init/Lean/Compiler/IR/UnreachBranches.lean b/library/Init/Lean/Compiler/IR/UnreachBranches.lean
index d13a005891..c3b7251f07 100644
--- a/library/Init/Lean/Compiler/IR/UnreachBranches.lean
+++ b/library/Init/Lean/Compiler/IR/UnreachBranches.lean
@@ -221,6 +221,7 @@ partial def interpFnBody : FnBody → M Unit
 
 def inferStep : M Bool :=
 do ctx ← read;
+   modify $ fun s => { assignments := ctx.decls.map $ fun _ => {}, .. s };
    ctx.decls.size.mfold (fun idx modified => do
      match ctx.decls.get! idx with
      | Decl.fdecl fid ys _ b => do