From bfecc4e1dd5744fb7c0d2b006a827d18a5408198 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jurko=20Gospodneti=C4=87?= <jurko.gospodnetic@pke.hr>
Date: Sat, 11 Aug 2012 14:49:52 +0000
Subject: [PATCH] Boost Build cleanup - build-system.jam module's
 should-clean-project() rule result caching updated to correctly cache both
 true and false values. This got 'pessimized' a bit when we started using
 values directly convertable to false (i.e. undefined value or empty string)
 as return values for the result false instead of the string "false".

[SVN r79969]
---
 v2/build-system.jam | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/v2/build-system.jam b/v2/build-system.jam
index 68f0dbec9..6b1c026f6 100644
--- a/v2/build-system.jam
+++ b/v2/build-system.jam
@@ -504,9 +504,9 @@ local rule process-explicit-toolset-requests
 #
 local rule should-clean-project ( project )
 {
-    if ! $(.should-clean-project.$(project))
+    if ! $(.should-clean-project.$(project))-is-defined
     {
-        local r ;
+        local r = "" ;
         if ! [ project.is-jamroot-module $(project) ]
         {
             local parent = [ project.attribute $(project) parent-module ] ;