Simplify _get_xdg_cache_dir in setupext.

anntzer · anntzer · commit 5cf10f83b4de · 2018-01-14T22:54:51.000-08:00
1. we don't support google app engine anymore.
2. in setupext, the cache dir is only used to cache the freetype
   tarball, so it's really not a huge deal if a cache dir cannot be
   located (this case is handled explicitly by the freetype build code).
diff --git a/setupext.py b/setupext.py
@@ -23,43 +23,18 @@
 PY3min = (sys.version_info[0] >= 3)
 
 
-def _get_home():
-    """Find user's home directory if possible.
-    Otherwise, returns None.
-
-    :see:
-        http://mail.python.org/pipermail/python-list/2005-February/325395.html
-    """
-    try:
-        if not PY3min and sys.platform == 'win32':
-            path = os.path.expanduser(b"~").decode(sys.getfilesystemencoding())
-        else:
-            path = os.path.expanduser("~")
-    except ImportError:
-        # This happens on Google App Engine (pwd module is not present).
-        pass
-    else:
-        if os.path.isdir(path):
-            return path
-    for evar in ('HOME', 'USERPROFILE', 'TMP'):
-        path = os.environ.get(evar)
-        if path is not None and os.path.isdir(path):
-            return path
-    return None
-
-
 def _get_xdg_cache_dir():
     """
-    Returns the XDG cache directory, according to the `XDG
-    base directory spec
-    <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_.
+    Return the XDG cache directory.
+
+    See https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
     """
-    path = os.environ.get('XDG_CACHE_HOME')
-    if path is None:
-        path = _get_home()
-        if path is not None:
-            path = os.path.join(path, '.cache', 'matplotlib')
-    return path
+    cache_dir = os.environ.get('XDG_CACHE_HOME')
+    if not cache_dir:
+        cache_dir = os.path.expanduser('~/.cache')
+        if cache_dir.startswith('~/'):  # Expansion failed.
+            return None
+    return os.path.join(cache_dir, 'matplotlib')
 
 
 # SHA256 hashes of the FreeType tarballs
