--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/pip/_internal/vcs/git.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,389 @@
+# The following comment should be removed at some point in the future.
+# mypy: disallow-untyped-defs=False
+
+from __future__ import absolute_import
+
+import logging
+import os.path
+import re
+
+from pip._vendor.packaging.version import parse as parse_version
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+from pip._vendor.six.moves.urllib import request as urllib_request
+
+from pip._internal.exceptions import BadCommand
+from pip._internal.utils.misc import display_path, hide_url
+from pip._internal.utils.subprocess import make_command
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.vcs.versioncontrol import (
+    RemoteNotFoundError,
+    VersionControl,
+    find_path_to_setup_from_repo_root,
+    vcs,
+)
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Tuple
+    from pip._internal.utils.misc import HiddenText
+    from pip._internal.vcs.versioncontrol import AuthInfo, RevOptions
+
+
+urlsplit = urllib_parse.urlsplit
+urlunsplit = urllib_parse.urlunsplit
+
+
+logger = logging.getLogger(__name__)
+
+
+HASH_REGEX = re.compile('^[a-fA-F0-9]{40}$')
+
+
+def looks_like_hash(sha):
+    return bool(HASH_REGEX.match(sha))
+
+
+class Git(VersionControl):
+    name = 'git'
+    dirname = '.git'
+    repo_name = 'clone'
+    schemes = (
+        'git', 'git+http', 'git+https', 'git+ssh', 'git+git', 'git+file',
+    )
+    # Prevent the user's environment variables from interfering with pip:
+    # https://github.com/pypa/pip/issues/1130
+    unset_environ = ('GIT_DIR', 'GIT_WORK_TREE')
+    default_arg_rev = 'HEAD'
+
+    @staticmethod
+    def get_base_rev_args(rev):
+        return [rev]
+
+    def is_immutable_rev_checkout(self, url, dest):
+        # type: (str, str) -> bool
+        _, rev_options = self.get_url_rev_options(hide_url(url))
+        if not rev_options.rev:
+            return False
+        if not self.is_commit_id_equal(dest, rev_options.rev):
+            # the current commit is different from rev,
+            # which means rev was something else than a commit hash
+            return False
+        # return False in the rare case rev is both a commit hash
+        # and a tag or a branch; we don't want to cache in that case
+        # because that branch/tag could point to something else in the future
+        is_tag_or_branch = bool(
+            self.get_revision_sha(dest, rev_options.rev)[0]
+        )
+        return not is_tag_or_branch
+
+    def get_git_version(self):
+        VERSION_PFX = 'git version '
+        version = self.run_command(['version'], show_stdout=False)
+        if version.startswith(VERSION_PFX):
+            version = version[len(VERSION_PFX):].split()[0]
+        else:
+            version = ''
+        # get first 3 positions of the git version because
+        # on windows it is x.y.z.windows.t, and this parses as
+        # LegacyVersion which always smaller than a Version.
+        version = '.'.join(version.split('.')[:3])
+        return parse_version(version)
+
+    @classmethod
+    def get_current_branch(cls, location):
+        """
+        Return the current branch, or None if HEAD isn't at a branch
+        (e.g. detached HEAD).
+        """
+        # git-symbolic-ref exits with empty stdout if "HEAD" is a detached
+        # HEAD rather than a symbolic ref.  In addition, the -q causes the
+        # command to exit with status code 1 instead of 128 in this case
+        # and to suppress the message to stderr.
+        args = ['symbolic-ref', '-q', 'HEAD']
+        output = cls.run_command(
+            args, extra_ok_returncodes=(1, ), show_stdout=False, cwd=location,
+        )
+        ref = output.strip()
+
+        if ref.startswith('refs/heads/'):
+            return ref[len('refs/heads/'):]
+
+        return None
+
+    def export(self, location, url):
+        # type: (str, HiddenText) -> None
+        """Export the Git repository at the url to the destination location"""
+        if not location.endswith('/'):
+            location = location + '/'
+
+        with TempDirectory(kind="export") as temp_dir:
+            self.unpack(temp_dir.path, url=url)
+            self.run_command(
+                ['checkout-index', '-a', '-f', '--prefix', location],
+                show_stdout=False, cwd=temp_dir.path
+            )
+
+    @classmethod
+    def get_revision_sha(cls, dest, rev):
+        """
+        Return (sha_or_none, is_branch), where sha_or_none is a commit hash
+        if the revision names a remote branch or tag, otherwise None.
+
+        Args:
+          dest: the repository directory.
+          rev: the revision name.
+        """
+        # Pass rev to pre-filter the list.
+        output = cls.run_command(['show-ref', rev], cwd=dest,
+                                 show_stdout=False, on_returncode='ignore')
+        refs = {}
+        for line in output.strip().splitlines():
+            try:
+                sha, ref = line.split()
+            except ValueError:
+                # Include the offending line to simplify troubleshooting if
+                # this error ever occurs.
+                raise ValueError('unexpected show-ref line: {!r}'.format(line))
+
+            refs[ref] = sha
+
+        branch_ref = 'refs/remotes/origin/{}'.format(rev)
+        tag_ref = 'refs/tags/{}'.format(rev)
+
+        sha = refs.get(branch_ref)
+        if sha is not None:
+            return (sha, True)
+
+        sha = refs.get(tag_ref)
+
+        return (sha, False)
+
+    @classmethod
+    def resolve_revision(cls, dest, url, rev_options):
+        # type: (str, HiddenText, RevOptions) -> RevOptions
+        """
+        Resolve a revision to a new RevOptions object with the SHA1 of the
+        branch, tag, or ref if found.
+
+        Args:
+          rev_options: a RevOptions object.
+        """
+        rev = rev_options.arg_rev
+        # The arg_rev property's implementation for Git ensures that the
+        # rev return value is always non-None.
+        assert rev is not None
+
+        sha, is_branch = cls.get_revision_sha(dest, rev)
+
+        if sha is not None:
+            rev_options = rev_options.make_new(sha)
+            rev_options.branch_name = rev if is_branch else None
+
+            return rev_options
+
+        # Do not show a warning for the common case of something that has
+        # the form of a Git commit hash.
+        if not looks_like_hash(rev):
+            logger.warning(
+                "Did not find branch or tag '%s', assuming revision or ref.",
+                rev,
+            )
+
+        if not rev.startswith('refs/'):
+            return rev_options
+
+        # If it looks like a ref, we have to fetch it explicitly.
+        cls.run_command(
+            make_command('fetch', '-q', url, rev_options.to_args()),
+            cwd=dest,
+        )
+        # Change the revision to the SHA of the ref we fetched
+        sha = cls.get_revision(dest, rev='FETCH_HEAD')
+        rev_options = rev_options.make_new(sha)
+
+        return rev_options
+
+    @classmethod
+    def is_commit_id_equal(cls, dest, name):
+        """
+        Return whether the current commit hash equals the given name.
+
+        Args:
+          dest: the repository directory.
+          name: a string name.
+        """
+        if not name:
+            # Then avoid an unnecessary subprocess call.
+            return False
+
+        return cls.get_revision(dest) == name
+
+    def fetch_new(self, dest, url, rev_options):
+        # type: (str, HiddenText, RevOptions) -> None
+        rev_display = rev_options.to_display()
+        logger.info('Cloning %s%s to %s', url, rev_display, display_path(dest))
+        self.run_command(make_command('clone', '-q', url, dest))
+
+        if rev_options.rev:
+            # Then a specific revision was requested.
+            rev_options = self.resolve_revision(dest, url, rev_options)
+            branch_name = getattr(rev_options, 'branch_name', None)
+            if branch_name is None:
+                # Only do a checkout if the current commit id doesn't match
+                # the requested revision.
+                if not self.is_commit_id_equal(dest, rev_options.rev):
+                    cmd_args = make_command(
+                        'checkout', '-q', rev_options.to_args(),
+                    )
+                    self.run_command(cmd_args, cwd=dest)
+            elif self.get_current_branch(dest) != branch_name:
+                # Then a specific branch was requested, and that branch
+                # is not yet checked out.
+                track_branch = 'origin/{}'.format(branch_name)
+                cmd_args = [
+                    'checkout', '-b', branch_name, '--track', track_branch,
+                ]
+                self.run_command(cmd_args, cwd=dest)
+
+        #: repo may contain submodules
+        self.update_submodules(dest)
+
+    def switch(self, dest, url, rev_options):
+        # type: (str, HiddenText, RevOptions) -> None
+        self.run_command(
+            make_command('config', 'remote.origin.url', url),
+            cwd=dest,
+        )
+        cmd_args = make_command('checkout', '-q', rev_options.to_args())
+        self.run_command(cmd_args, cwd=dest)
+
+        self.update_submodules(dest)
+
+    def update(self, dest, url, rev_options):
+        # type: (str, HiddenText, RevOptions) -> None
+        # First fetch changes from the default remote
+        if self.get_git_version() >= parse_version('1.9.0'):
+            # fetch tags in addition to everything else
+            self.run_command(['fetch', '-q', '--tags'], cwd=dest)
+        else:
+            self.run_command(['fetch', '-q'], cwd=dest)
+        # Then reset to wanted revision (maybe even origin/master)
+        rev_options = self.resolve_revision(dest, url, rev_options)
+        cmd_args = make_command('reset', '--hard', '-q', rev_options.to_args())
+        self.run_command(cmd_args, cwd=dest)
+        #: update submodules
+        self.update_submodules(dest)
+
+    @classmethod
+    def get_remote_url(cls, location):
+        """
+        Return URL of the first remote encountered.
+
+        Raises RemoteNotFoundError if the repository does not have a remote
+        url configured.
+        """
+        # We need to pass 1 for extra_ok_returncodes since the command
+        # exits with return code 1 if there are no matching lines.
+        stdout = cls.run_command(
+            ['config', '--get-regexp', r'remote\..*\.url'],
+            extra_ok_returncodes=(1, ), show_stdout=False, cwd=location,
+        )
+        remotes = stdout.splitlines()
+        try:
+            found_remote = remotes[0]
+        except IndexError:
+            raise RemoteNotFoundError
+
+        for remote in remotes:
+            if remote.startswith('remote.origin.url '):
+                found_remote = remote
+                break
+        url = found_remote.split(' ')[1]
+        return url.strip()
+
+    @classmethod
+    def get_revision(cls, location, rev=None):
+        if rev is None:
+            rev = 'HEAD'
+        current_rev = cls.run_command(
+            ['rev-parse', rev], show_stdout=False, cwd=location,
+        )
+        return current_rev.strip()
+
+    @classmethod
+    def get_subdirectory(cls, location):
+        """
+        Return the path to setup.py, relative to the repo root.
+        Return None if setup.py is in the repo root.
+        """
+        # find the repo root
+        git_dir = cls.run_command(
+            ['rev-parse', '--git-dir'],
+            show_stdout=False, cwd=location).strip()
+        if not os.path.isabs(git_dir):
+            git_dir = os.path.join(location, git_dir)
+        repo_root = os.path.abspath(os.path.join(git_dir, '..'))
+        return find_path_to_setup_from_repo_root(location, repo_root)
+
+    @classmethod
+    def get_url_rev_and_auth(cls, url):
+        # type: (str) -> Tuple[str, Optional[str], AuthInfo]
+        """
+        Prefixes stub URLs like 'user@hostname:user/repo.git' with 'ssh://'.
+        That's required because although they use SSH they sometimes don't
+        work with a ssh:// scheme (e.g. GitHub). But we need a scheme for
+        parsing. Hence we remove it again afterwards and return it as a stub.
+        """
+        # Works around an apparent Git bug
+        # (see https://article.gmane.org/gmane.comp.version-control.git/146500)
+        scheme, netloc, path, query, fragment = urlsplit(url)
+        if scheme.endswith('file'):
+            initial_slashes = path[:-len(path.lstrip('/'))]
+            newpath = (
+                initial_slashes +
+                urllib_request.url2pathname(path)
+                .replace('\\', '/').lstrip('/')
+            )
+            url = urlunsplit((scheme, netloc, newpath, query, fragment))
+            after_plus = scheme.find('+') + 1
+            url = scheme[:after_plus] + urlunsplit(
+                (scheme[after_plus:], netloc, newpath, query, fragment),
+            )
+
+        if '://' not in url:
+            assert 'file:' not in url
+            url = url.replace('git+', 'git+ssh://')
+            url, rev, user_pass = super(Git, cls).get_url_rev_and_auth(url)
+            url = url.replace('ssh://', '')
+        else:
+            url, rev, user_pass = super(Git, cls).get_url_rev_and_auth(url)
+
+        return url, rev, user_pass
+
+    @classmethod
+    def update_submodules(cls, location):
+        if not os.path.exists(os.path.join(location, '.gitmodules')):
+            return
+        cls.run_command(
+            ['submodule', 'update', '--init', '--recursive', '-q'],
+            cwd=location,
+        )
+
+    @classmethod
+    def controls_location(cls, location):
+        if super(Git, cls).controls_location(location):
+            return True
+        try:
+            r = cls.run_command(['rev-parse'],
+                                cwd=location,
+                                show_stdout=False,
+                                on_returncode='ignore',
+                                log_failed_cmd=False)
+            return not r
+        except BadCommand:
+            logger.debug("could not determine if %s is under git control "
+                         "because git is not available", location)
+            return False
+
+
+vcs.register(Git)