From d11e3e4ef342b7723b3cf554fde7677873c47040 Mon Sep 17 00:00:00 2001
From: Steven Watanabe <steven@providere-consulting.com>
Date: Tue, 21 Aug 2018 10:45:18 -0600
Subject: [PATCH] Don't break other toolsets that inherit from msvc (such as
 clang-win).  Refs #330.

---
 src/tools/msvc.jam | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/tools/msvc.jam b/src/tools/msvc.jam
index f8979d7ea..1313bfc78 100644
--- a/src/tools/msvc.jam
+++ b/src/tools/msvc.jam
@@ -1077,6 +1077,11 @@ local rule set-setup-command ( targets * : properties * )
     if ! [ on $(targets) return $(.SETUP) ]
     {
         local setup-script = [ on $(targets) return $(.SETUP-SCRIPT) ] ;
+        # If no setup script was given, then we don't need to do anything.
+        if ! $(setup-script)
+        {
+            return ;
+        }
         local setup-options = [ on $(targets) return $(.SETUP-OPTIONS) ] ;
         local key = .setup-command-$(setup-script:E=)-$(setup-options:E=) ;
         if ! $($(key))