Hans Leidekker : msi: Avoid an out of bounds access in msi_build_directory_name.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: b7cefc999701a5c2ff8ffc5c5f3da77ff82a874d
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=b7cefc999701a5c2ff8ffc5c5f3da77ff82a874d

Author: Hans Leidekker <hans at codeweavers.com>
Date:   Wed Aug  1 11:54:18 2012 +0200

msi: Avoid an out of bounds access in msi_build_directory_name.

---

 dlls/msi/action.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/dlls/msi/action.c b/dlls/msi/action.c
index 1ad3bc2..e1d2f2a 100644
--- a/dlls/msi/action.c
+++ b/dlls/msi/action.c
@@ -2154,7 +2154,7 @@ WCHAR *msi_build_directory_name( DWORD count, ... )
         const WCHAR *str = va_arg( va, const WCHAR * );
         if (!str) continue;
         strcatW( dir, str );
-        if ( i + 1 != count && dir[strlenW( dir ) - 1] != '\\') strcatW( dir, szBackSlash );
+        if ( i + 1 != count && dir[0] && dir[strlenW( dir ) - 1] != '\\') strcatW( dir, szBackSlash );
     }
     va_end( va );
     return dir;