waf: make mkdir_p on a empty string not recurse forever

diff --git a/buildtools/wafsamba/samba_utils.py b/buildtools/wafsamba/samba_utils.py
index 563009e0938d23a504764366727f79ba6b8a834a..b1ddc5a99eb894808a8354b025c1ae34ce3d40c1 100644 (file)
--- a/buildtools/wafsamba/samba_utils.py
+++ b/buildtools/wafsamba/samba_utils.py
@@ -308,7 +308,7 @@ def recursive_dirlist(dir, relbase, pattern=None):
 
 def mkdir_p(dir):
     '''like mkdir -p'''
-    if os.path.isdir(dir):
+    if not dir or os.path.isdir(dir):
         return
     mkdir_p(os.path.dirname(dir))
     os.mkdir(dir)