Address previous review comments

docs/html/reference/pip_install.rst

@@ -417,8 +417,8 @@ making fewer network calls).
 Mercurial
 ~~~~~~~~~
 
-The supported schemes are: ``hg+http``, ``hg+https``,
-``hg+static-http``, ``hg+ssh`` and ``hg+file``.
+The supported schemes are: ``hg+file``, ``hg+http``, ``hg+https``,
+``hg+static-http``, and ``hg+ssh``.
 
 Here are the supported forms::
 

src/pip/_internal/vcs/mercurial.py

@@ -23,7 +23,7 @@ class Mercurial(VersionControl):
     dirname = '.hg'
     repo_name = 'clone'
     schemes = (
-        'hg', 'hg+http', 'hg+https', 'hg+ssh', 'hg+static-http', 'hg+file'
+        'hg', 'hg+file', 'hg+http', 'hg+https', 'hg+ssh', 'hg+static-http',
     )
 
     @staticmethod

tests/functional/test_install.py

@@ -336,10 +336,11 @@ def test_install_editable_uninstalls_existing_from_path(script, data):
 def test_basic_install_editable_from_hg(script, tmpdir):
     """Test cloning and hg+file install from Mercurial."""
     pkg_path = _create_test_package(script, name='testpackage', vcs='hg')
-    args = ['install', '-e', 'hg+%s#egg=testpackage' % path_to_url(pkg_path)]
+    url = 'hg+{}#egg=testpackage'.format(path_to_url(pkg_path))
+    assert url.startswith('hg+file')
+    args = ['install', '-e', url]
     result = script.pip(*args)
     result.assert_installed('testpackage', with_files=['.hg'])
-    assert path_to_url(pkg_path).startswith("file://")
 
 
 @need_mercurial