view hgext/schemes.py @ 47315:825d5a5907b4

exewrapper: avoid directly linking against python3X.dll

Subsequent code calls `LoadLibrary()` to attempt to load the DLL, but because of
this symbol reference, there is an attempt to load the DLL used during the build
prior to `_main()` running.  This causes the whole process to fail if the DLL
isn't in the standard search path.  That also means it will never load the DLL
for HackableMercurial.  (Maybe we should get rid of that for py3, since you can
install python for a user without admin rights?)

This could also be resolved by calling `GetProcAddress()` on the symbol and
dereferencing it, but using the environment variable is consistent with the
*.bat file since fc8a5c9ecee0.  (The environment variable persists after the
interpreter is initialized.)

Far more concerning is somehow I've gotten my system into a state where setting
the flag causes any output to the pager to be lost (as if it wasn't set at all)
in MSYS, cmd.exe, WSL, and PowerShell using py3.9.0, but the environment
variable works properly.  I'm sure this flag worked on some versions of py3, so
I'm not sure what's going on here.  This is might be related to init config
related changes in 3.8[1], since it works with 3.7.8, but fails with 3.8.1.
Somebody who understands encoding issues better than I do should give some
thought to if we need to make some changes to our encoding strategy on Windows
with py3.

With or without the flag/envvar, there is proper output if the command is
directly paged by piping to `more.com` (in any environment) or `less` (in MSYS
and WSL), or if paging is disabled with `--pager=no`.  Legacy mode is required
though when Mercurial decides to spin up a pager.

[1] https://bugs.python.org/issue41941

Differential Revision: https://phab.mercurial-scm.org/D10756

# Copyright 2009, Alexander Solovyov <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""extend schemes with shortcuts to repository swarms

This extension allows you to specify shortcuts for parent URLs with a
lot of repositories to act like a scheme, for example::

  [schemes]
  py = http://code.python.org/hg/

After that you can use it like::

  hg clone py://trunk/

Additionally there is support for some more complex schemas, for
example used by Google Code::

  [schemes]
  gcode = http://{1}.googlecode.com/hg/

The syntax is taken from Mercurial templates, and you have unlimited
number of variables, starting with ``{1}`` and continuing with
``{2}``, ``{3}`` and so on. This variables will receive parts of URL
supplied, split by ``/``. Anything not specified as ``{part}`` will be
just appended to an URL.

For convenience, the extension adds these schemes by default::

  [schemes]
  py = http://hg.python.org/
  bb = https://bitbucket.org/
  bb+ssh = ssh://[e-mail]/
  gcode = https://{1}.googlecode.com/hg/
  kiln = https://{1}.kilnhg.com/Repo/

You can override a predefined scheme by defining a new scheme with the
same name.
"""
from __future__ import absolute_import

import os
import re

from mercurial.i18n import _
from mercurial import (
    error,
    extensions,
    hg,
    pycompat,
    registrar,
    templater,
)
from mercurial.utils import (
    urlutil,
)

cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'

_partre = re.compile(br'{(\d+)\}')


class ShortRepository(object):
    def __init__(self, url, scheme, templater):
        self.scheme = scheme
        self.templater = templater
        self.url = url
        try:
            self.parts = max(map(int, _partre.findall(self.url)))
        except ValueError:
            self.parts = 0

    def __repr__(self):
        return b'<ShortRepository: %s>' % self.scheme

    def instance(self, ui, url, create, intents=None, createopts=None):
        url = self.resolve(url)
        return hg._peerlookup(url).instance(
            ui, url, create, intents=intents, createopts=createopts
        )

    def resolve(self, url):
        # Should this use the urlutil.url class, or is manual parsing better?
        try:
            url = url.split(b'://', 1)[1]
        except IndexError:
            raise error.Abort(_(b"no '://' in scheme url '%s'") % url)
        parts = url.split(b'/', self.parts)
        if len(parts) > self.parts:
            tail = parts[-1]
            parts = parts[:-1]
        else:
            tail = b''
        context = {b'%d' % (i + 1): v for i, v in enumerate(parts)}
        return b''.join(self.templater.process(self.url, context)) + tail


def hasdriveletter(orig, path):
    if path:
        for scheme in schemes:
            if path.startswith(scheme + b':'):
                return False
    return orig(path)


schemes = {
    b'py': b'http://hg.python.org/',
    b'bb': b'https://bitbucket.org/',
    b'bb+ssh': b'ssh://[e-mail]/',
    b'gcode': b'https://{1}.googlecode.com/hg/',
    b'kiln': b'https://{1}.kilnhg.com/Repo/',
}


def extsetup(ui):
    schemes.update(dict(ui.configitems(b'schemes')))
    t = templater.engine(templater.parse)
    for scheme, url in schemes.items():
        if (
            pycompat.iswindows
            and len(scheme) == 1
            and scheme.isalpha()
            and os.path.exists(b'%s:\\' % scheme)
        ):
            raise error.Abort(
                _(
                    b'custom scheme %s:// conflicts with drive '
                    b'letter %s:\\\n'
                )
                % (scheme, scheme.upper())
            )
        hg.schemes[scheme] = ShortRepository(url, scheme, t)

    extensions.wrapfunction(urlutil, b'hasdriveletter', hasdriveletter)


@command(b'debugexpandscheme', norepo=True)
def expandscheme(ui, url, **opts):
    """given a repo path, provide the scheme-expanded path"""
    repo = hg._peerlookup(url)
    if isinstance(repo, ShortRepository):
        url = repo.resolve(url)
    ui.write(url + b'\n')