`read_configuration` now chdirs and tests for file.

setuptools/config.py

@@ -5,7 +5,7 @@ import sys
 from collections import defaultdict
 from functools import partial
 
-from distutils.errors import DistutilsOptionError
+from distutils.errors import DistutilsOptionError, DistutilsFileError
 from setuptools.py26compat import import_module
 from setuptools.extern.six import string_types
 
@@ -23,6 +23,15 @@ def read_configuration(filepath, find_others=False):
     """
     from setuptools.dist import Distribution, _Distribution
 
+    filepath = os.path.abspath(filepath)
+
+    if not os.path.isfile(filepath):
+        raise DistutilsFileError(
+            'Configuration file %s does not exist.' % filepath)
+
+    current_directory = os.getcwd()
+    os.chdir(os.path.dirname(filepath))
+
     dist = Distribution()
 
     filenames = dist.find_config_files() if find_others else []
@@ -33,6 +42,8 @@ def read_configuration(filepath, find_others=False):
 
     handlers = parse_configuration(dist, dist.command_options)
 
+    os.chdir(current_directory)
+
     return configuration_to_dict(handlers)
 
 

setuptools/tests/test_config.py

 import contextlib
 import pytest
-from distutils.errors import DistutilsOptionError
+from distutils.errors import DistutilsOptionError, DistutilsFileError
 from setuptools.dist import Distribution
 from setuptools.config import ConfigHandler, read_configuration
 
@@ -69,6 +69,10 @@ class TestConfigurationReader:
         assert config_dict['metadata']['keywords'] == ['one', 'two']
         assert config_dict['options']['scripts'] == ['bin/a.py', 'bin/b.py']
 
+    def test_no_config(self, tmpdir):
+        with pytest.raises(DistutilsFileError):
+            read_configuration('%s' % tmpdir.join('setup.cfg'))
+
 
 class TestMetadata: