From a0b08700d1a0affe59ce2428cc8d204362924ad7 Mon Sep 17 00:00:00 2001
From: Chong Yidong <cyd@stupidchicken.com>
Date: Tue, 24 Jan 2006 18:35:25 +0000
Subject: * alloc.c (allocate_string_data): Update next_free immediately, to 
 reduce risk of memory clobberage.

---
 src/alloc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'src/alloc.c')

diff --git a/src/alloc.c b/src/alloc.c
index d81a9bf853b..f0c77a26710 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -1978,6 +1978,8 @@ allocate_string_data (s, nchars, nbytes)
   old_nbytes = GC_STRING_BYTES (s);
 
   data = b->next_free;
+  b->next_free = (struct sdata *) ((char *) data + needed + GC_STRING_EXTRA);
+
   data->string = s;
   s->data = SDATA_DATA (data);
 #ifdef GC_CHECK_STRING_BYTES
@@ -1990,7 +1992,6 @@ allocate_string_data (s, nchars, nbytes)
   bcopy (string_overrun_cookie, (char *) data + needed,
 	 GC_STRING_OVERRUN_COOKIE_SIZE);
 #endif
-  b->next_free = (struct sdata *) ((char *) data + needed + GC_STRING_EXTRA);
 
   /* If S had already data assigned, mark that as free by setting its
      string back-pointer to null, and recording the size of the data
-- 
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