From 0b783f80b7b6b60acc31e78beb7a90d47f3d444e Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Fri, 23 Mar 2012 15:55:11 -0600
Subject: [PATCH] fix problem with measuring text and font substitutions

---
 collects/racket/draw/private/dc.rkt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/collects/racket/draw/private/dc.rkt b/collects/racket/draw/private/dc.rkt
index eea3a06dba..8dd4659ee1 100644
--- a/collects/racket/draw/private/dc.rkt
+++ b/collects/racket/draw/private/dc.rkt
@@ -1286,7 +1286,8 @@
               ;; breaks the string into multiple layouts.
               (let loop ([s s] [draw-mode draw-mode] [measured? #f] [w 0.0] [h 0.0] [d 0.0] [a 0.0])
                 (cond
-                 [(not s)
+                 [(or (not s)
+                      (equal? s "")) ; can happen if last char is substituted
                   (when rotate? (cairo_restore cr))
                   (values w h d a)]
                  [else