From 3f7a7d28c0a8f2acde5284b4bbc7b61f6ce5da47 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 9 May 2006 15:52:06 +0000
Subject: [PATCH] minor optimization: don't wrap a 'begin' that contains a
 single expression

svn: r2877
---
 collects/errortrace/errortrace-lib.ss | 2 +-
 collects/errortrace/stacktrace.ss     | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/collects/errortrace/errortrace-lib.ss b/collects/errortrace/errortrace-lib.ss
index 535bea302f..2590d5e347 100644
--- a/collects/errortrace/errortrace-lib.ss
+++ b/collects/errortrace/errortrace-lib.ss
@@ -305,7 +305,7 @@
                             e
                             (namespace-syntax-introduce
                              (datum->syntax-object #f e))))])
-               e2)
+	       e2)
              e)
          immediate-eval?))))
 
diff --git a/collects/errortrace/stacktrace.ss b/collects/errortrace/stacktrace.ss
index f1e34b8676..9dca9fe5a2 100644
--- a/collects/errortrace/stacktrace.ss
+++ b/collects/errortrace/stacktrace.ss
@@ -473,6 +473,11 @@
                             (rebuild expr (list (cons #'rhs new-rhs))))))]
 
              ;; Wrap subexpressions only
+	     [(begin e)
+	      ;; Single expression: no mark
+	      (certify
+	       expr
+	       #`(begin #,(annotate (syntax e) trans?)))]
              [(begin . body)
               (with-mark expr
                          (certify