BLD: Fix has_include_file side-effect

Kojoley · Kojoley · commit d527a82995b5 · 2017-11-01T18:46:43.000+03:00
The passed argument would be modified by function while it not designed to.
diff --git a/setupext.py b/setupext.py
@@ -151,7 +151,8 @@ def has_include_file(include_dirs, filename):
     directories in `include_dirs`.
     """
     if sys.platform == 'win32':
-        include_dirs += os.environ.get('INCLUDE', '.').split(';')
+        include_dirs = list(include_dirs)  # copy before modify
+        include_dirs += os.environ.get('INCLUDE', '.').split(os.pathsep)
     for dir in include_dirs:
         if os.path.exists(os.path.join(dir, filename)):
             return True
