From ea6968f1d9e48d4c13b86a558a333b9482dacbdd Mon Sep 17 00:00:00 2001
From: Vincent St-Amour <stamourv@racket-lang.org>
Date: Mon, 2 Nov 2015 13:26:30 -0600
Subject: [PATCH] Don't attempt to unfold pair opts when we have no type info.

Fixes compilation of the `midi-readwrite` package.
---
 typed-racket-lib/typed-racket/optimizer/pair.rkt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/typed-racket-lib/typed-racket/optimizer/pair.rkt b/typed-racket-lib/typed-racket/optimizer/pair.rkt
index a5f97a30..54f2b657 100644
--- a/typed-racket-lib/typed-racket/optimizer/pair.rkt
+++ b/typed-racket-lib/typed-racket/optimizer/pair.rkt
@@ -137,6 +137,7 @@
                             [(tc-result1: t) t])]
                      [res #'e.arg])
               ([accessor (in-list (reverse (syntax->list #'e.alt)))])
+            #:break (not t)
             (cond
              [(subtype t (-pair Univ Univ)) ; safe to optimize this one layer
               (syntax-parse accessor