From b52bc06efc7a59bd262994eda285d2b125b767d7 Mon Sep 17 00:00:00 2001
From: Nigel Metheringham <nigel@exim.org>
Date: Fri, 12 Dec 2008 14:51:47 +0000
Subject: [PATCH] Make whitespace strings compare euqal to zero. fixes: bug
 #749

---
 doc/doc-txt/ChangeLog |  5 ++++-
 src/src/expand.c      | 19 ++++++++++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 1e4774067..dd9352965 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.558 2008/12/12 14:44:25 nm4 Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.559 2008/12/12 14:51:47 nm4 Exp $
 
 Change log file for Exim from version 4.21
 -------------------------------------------
@@ -83,6 +83,9 @@ NM/09 Bugzilla 787: Potential buffer overflow in string_format
 NM/10 Bugzilla 770: Problem on some platforms modifying the len parameter to accept()
       Patch provided by Maxim Dounin
 
+NM/11 Bugzilla 749: Preserve old behaviour of blanks comparing equal to zero.
+      Patch provided by Phil Pennock
+
 
 Exim version 4.69
 -----------------
diff --git a/src/src/expand.c b/src/src/expand.c
index cd84294ae..599dd9c0d 100644
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/expand.c,v 1.96 2008/08/07 11:05:03 fanf2 Exp $ */
+/* $Cambridge: exim/src/src/expand.c,v 1.97 2008/12/12 14:51:47 nm4 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -5874,6 +5874,23 @@ systems, so we set it zero ourselves. */
 
 errno = 0;
 expand_string_message = NULL;               /* Indicates no error */
+
+/* Before Exim 4.64, strings consisting entirely of whitespace compared
+equal to 0.  Unfortunately, people actually relied upon that, so preserve
+the behaviour explicitly.  Stripping leading whitespace is a harmless
+noop change since strtol skips it anyway (provided that there is a number
+to find at all). */
+if (isspace(*s))
+  {
+  while (isspace(*s)) ++s;
+  if (*s == '\0')
+    {
+      DEBUG(D_expand)
+       debug_printf("treating blank string as number 0\n");
+      return 0;
+    }
+  }
+
 value = strtol(CS s, CSS &endptr, 10);
 
 if (endptr == s)
-- 
2.30.2