From fa179c9c7aeb8b8ce7ceb43e9c00b58af5506e47 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Wed, 7 Jun 2006 15:07:34 +0000
Subject: [PATCH] avoid infinite loop in sync when a mzc-generated function in
 an event generator for a struct, and it returns the struct itself

svn: r3262
---
 src/mzscheme/src/struct.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mzscheme/src/struct.c b/src/mzscheme/src/struct.c
index ac02450f6b..b40bcff07a 100644
--- a/src/mzscheme/src/struct.c
+++ b/src/mzscheme/src/struct.c
@@ -804,6 +804,8 @@ static int evt_struct_is_ready(Scheme_Object *o, Scheme_Schedule_Info *sinfo)
       result = scheme_apply(f, 1, a);
 
       if (scheme_is_evt(result)) {
+	SCHEME_USE_FUEL(1); /* Needed beause an apply of a mzc-generated function
+			       might not check for breaks. */
 	scheme_set_sync_target(sinfo, result, NULL, NULL, 0, 1);
 	return 0;
       }