make sure paths found by find_command are files

pip/util.py

@@ -86,9 +86,9 @@ def find_command(cmd, paths=None, pathext=None):
  for ext in pathext:
  # then including the extension
  cmd_path_ext = cmd_path + ext
- if os.path.exists(cmd_path_ext):
+ if os.path.isfile(cmd_path_ext):
  return cmd_path_ext
- if os.path.exists(cmd_path):
+ if os.path.isfile(cmd_path):
  return cmd_path
  return None
 

tests/test_basic.py

@@ -483,3 +483,18 @@ def test_install_package_which_contains_dev_in_name():
  egg_info_folder = env.site_packages/'django_devserver-0.0.4-py%s.egg-info' % pyversion
  assert devserver_folder in result.files_created, str(result.stdout)
  assert egg_info_folder in result.files_created, str(result)
+
+def test_find_command_folder_in_path():
+ """
+ If a folder named e.g. 'git' is in PATH, and find_command is looking for
+ the 'git' executable, it should not match the folder, but rather keep
+ looking.
+ """
+ env = reset_env()
+ mkdir('path_one'); path_one = env.scratch_path/'path_one'
+ mkdir(path_one/'foo')
+ mkdir('path_two'); path_two = env.scratch_path/'path_two'
+ write_file(path_two/'foo', '# nothing')
+ from pip.util import find_command
+ found_path = find_command('foo', map(str, [path_one, path_two]))
+ assert found_path == path_two/'foo'