From 0100f88e298c6766d60108537010ede0f83da1dd Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Mon, 24 Sep 2012 11:15:32 -0400
Subject: [PATCH] FindBoost: Construct a clean Boost_LIBRARIES value

Construct the value from scratch based on the component library list.
Avoid accumulating values from repeated find_package(Boost) calls.
If Boost is not found, Boost_LIBRARIES should be empty.
---
 Modules/FindBoost.cmake | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Modules/FindBoost.cmake b/Modules/FindBoost.cmake
index 1a9dfbdaa..a2036a624 100644
--- a/Modules/FindBoost.cmake
+++ b/Modules/FindBoost.cmake
@@ -1219,6 +1219,7 @@ endif()
 #  Notification to end user about what was found
 # ------------------------------------------------------------------------
 
+set(Boost_LIBRARIES "")
 if(Boost_FOUND)
   if(NOT Boost_FIND_QUIETLY)
     message(STATUS "Boost version: ${Boost_MAJOR_VERSION}.${Boost_MINOR_VERSION}.${Boost_SUBMINOR_VERSION}")
@@ -1232,7 +1233,7 @@ if(Boost_FOUND)
       if(NOT Boost_FIND_QUIETLY)
         message (STATUS "  ${COMPONENT}")
       endif()
-      set(Boost_LIBRARIES ${Boost_LIBRARIES} ${Boost_${UPPERCOMPONENT}_LIBRARY})
+      list(APPEND Boost_LIBRARIES ${Boost_${UPPERCOMPONENT}_LIBRARY})
     endif()
   endforeach()
 else()