Update sdist_add_defaults to match CPython db8bb1bd6ac5

setuptools/command/py36compat.py

@@ -3,6 +3,8 @@ from glob import glob
 from distutils.util import convert_path
 from distutils.command import sdist
 
+from setuptools.extern.six.moves import filter
+
 
 class sdist_add_defaults:
     """
@@ -32,6 +34,23 @@ class sdist_add_defaults:
         self._add_defaults_c_libs()
         self._add_defaults_scripts()
 
+    @staticmethod
+    def _cs_path_exists(fspath):
+        """
+        Case-sensitive path existence check
+
+        >>> sdist._cs_path_exists(__file__)
+        True
+        >>> sdist._cs_path_exists(__file__.upper())
+        False
+        """
+        if not os.path.exists(fspath):
+            return False
+        # make absolute so we always have a directory
+        abspath = os.path.abspath(fspath)
+        directory, filename = os.path.split(abspath)
+        return filename in os.listdir(directory)
+
     def _add_defaults_standards(self):
         standards = [self.READMES, self.distribution.script_name]
         for fn in standards:
@@ -39,7 +58,7 @@ class sdist_add_defaults:
                 alts = fn
                 got_it = False
                 for fn in alts:
-                    if os.path.exists(fn):
+                    if self._cs_path_exists(fn):
                         got_it = True
                         self.filelist.append(fn)
                         break
@@ -48,7 +67,7 @@ class sdist_add_defaults:
                     self.warn("standard file not found: should have one of " +
                               ', '.join(alts))
             else:
-                if os.path.exists(fn):
+                if self._cs_path_exists(fn):
                     self.filelist.append(fn)
                 else:
                     self.warn("standard file '%s' not found" % fn)