From 18a253732db75afb713ce1bdd07d593780a4590b Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Tue, 22 Oct 2013 13:59:56 -0400
Subject: [PATCH] CMakeDetermineCompilerId: Do not test vendor without a
 compiler

If no CMAKE_${lang}_COMPILER is available then do not try to run
it to determine the compiler vendor.
---
 Modules/CMakeDetermineCompilerId.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/CMakeDetermineCompilerId.cmake b/Modules/CMakeDetermineCompilerId.cmake
index 0d7aa617b..bb260f62a 100644
--- a/Modules/CMakeDetermineCompilerId.cmake
+++ b/Modules/CMakeDetermineCompilerId.cmake
@@ -44,7 +44,7 @@ function(CMAKE_DETERMINE_COMPILER_ID lang flagvar src)
   endforeach()
 
   # If the compiler is still unknown, try to query its vendor.
-  if(NOT CMAKE_${lang}_COMPILER_ID)
+  if(CMAKE_${lang}_COMPILER AND NOT CMAKE_${lang}_COMPILER_ID)
     CMAKE_DETERMINE_COMPILER_ID_VENDOR(${lang})
   endif()