From b6d2a40a3efc6ea444f2570afbf81a9fd0450bbd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jurko=20Gospodneti=C4=87?= <jurko.gospodnetic@pke.hr>
Date: Mon, 18 Jun 2012 23:12:33 +0000
Subject: [PATCH] Refactored the Boost Build execnt.c module's maxline()
 function to cache its result instead of calling the GetVersionEx() Windows
 API on every call.

[SVN r78989]
---
 v2/engine/execnt.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/v2/engine/execnt.c b/v2/engine/execnt.c
index 02294c6f9..6e255f5b0 100644
--- a/v2/engine/execnt.c
+++ b/v2/engine/execnt.c
@@ -599,7 +599,7 @@ static void free_argv( char const * * args )
  *     http://support.microsoft.com/default.aspx?scid=kb;en-us;830473
  */
 
-int maxline()
+static int raw_maxline()
 {
     OSVERSIONINFO os_info;
     os_info.dwOSVersionInfoSize = sizeof( os_info );
@@ -610,6 +610,13 @@ int maxline()
     return 996;                                     /* NT 3.5.1 */
 }
 
+int maxline()
+{
+    static result;
+    if ( !result ) result = raw_maxline();
+    return result;
+}
+
 
 /*
  * Convert a command string into arguments as used by Unix spawnvp() API. The