style: run a patched black on a subset of mercurial

This applied black to the 20 smallest files in mercurial/:

    ls -S1 mercurial/*.py | tail -n20 | xargs black --skip-string-normalization

Note that a few files failed to format, presumably due to a bug in my
patch. The intent is to be able to compare results to D5064 with
https://github.com/python/black/pull/826 applied to black.

I skipped string normalization on this patch for clarity - in reality
I think we'd want one pass without string normalization, followed by
another to normalize strings (which is basically replacing ' with "
globally.)

# skip-blame mass-reformatting only

Differential Revision: https://phab.mercurial-scm.org/D6342

contrib/import-checker.py

@@ -1,749 +1,812 b''
 #!/usr/bin/env python
 
 from __future__ import absolute_import, print_function
 
 import ast
 import collections
 import os
 import sys
 
 # Import a minimal set of stdlib modules needed for list_stdlib_modules()
 # to work when run from a virtualenv.  The modules were chosen empirically
 # so that the return value matches the return value without virtualenv.
-if True: # disable lexical sorting checks
+if True:  # disable lexical sorting checks
     try:
         import BaseHTTPServer as basehttpserver
     except ImportError:
         basehttpserver = None
     import zlib
 
 import testparseutil
 
 # Whitelist of modules that symbols can be directly imported from.
 allowsymbolimports = (
     '__future__',
     'bzrlib',
     'hgclient',
     'mercurial',
     'mercurial.hgweb.common',
     'mercurial.hgweb.request',
     'mercurial.i18n',
     'mercurial.interfaces',
     'mercurial.node',
     # for revlog to re-export constant to extensions
     'mercurial.revlogutils.constants',
     'mercurial.revlogutils.flagutil',
     # for cffi modules to re-export pure functions
     'mercurial.pure.base85',
     'mercurial.pure.bdiff',
     'mercurial.pure.mpatch',
     'mercurial.pure.osutil',
     'mercurial.pure.parsers',
     # third-party imports should be directly imported
     'mercurial.thirdparty',
     'mercurial.thirdparty.attr',
     'mercurial.thirdparty.zope',
     'mercurial.thirdparty.zope.interface',
 )
 
 # Whitelist of symbols that can be directly imported.
-directsymbols = (
-    'demandimport',
-)
+directsymbols = ('demandimport',)
 
 # Modules that must be aliased because they are commonly confused with
 # common variables and can create aliasing and readability issues.
 requirealias = {
     'ui': 'uimod',
 }
 
+
 def usingabsolute(root):
     """Whether absolute imports are being used."""
     if sys.version_info[0] >= 3:
         return True
 
     for node in ast.walk(root):
         if isinstance(node, ast.ImportFrom):
             if node.module == '__future__':
                 for n in node.names:
                     if n.name == 'absolute_import':
                         return True
 
     return False
 
+
 def walklocal(root):
     """Recursively yield all descendant nodes but not in a different scope"""
     todo = collections.deque(ast.iter_child_nodes(root))
     yield root, False
     while todo:
         node = todo.popleft()
         newscope = isinstance(node, ast.FunctionDef)
         if not newscope:
             todo.extend(ast.iter_child_nodes(node))
         yield node, newscope
 
+
 def dotted_name_of_path(path):
     """Given a relative path to a source file, return its dotted module name.
 
     >>> dotted_name_of_path('mercurial/error.py')
     'mercurial.error'
     >>> dotted_name_of_path('zlibmodule.so')
     'zlib'
     """
     parts = path.replace(os.sep, '/').split('/')
-    parts[-1] = parts[-1].split('.', 1)[0] # remove .py and .so and .ARCH.so
+    parts[-1] = parts[-1].split('.', 1)[0]  # remove .py and .so and .ARCH.so
     if parts[-1].endswith('module'):
         parts[-1] = parts[-1][:-6]
     return '.'.join(parts)
 
+
 def fromlocalfunc(modulename, localmods):
     """Get a function to examine which locally defined module the
     target source imports via a specified name.
 
     `modulename` is an `dotted_name_of_path()`-ed source file path,
     which may have `.__init__` at the end of it, of the target source.
 
     `localmods` is a set of absolute `dotted_name_of_path()`-ed source file
     paths of locally defined (= Mercurial specific) modules.
 
     This function assumes that module names not existing in
     `localmods` are from the Python standard library.
 
     This function returns the function, which takes `name` argument,
     and returns `(absname, dottedpath, hassubmod)` tuple if `name`
     matches against locally defined module. Otherwise, it returns
     False.
 
     It is assumed that `name` doesn't have `.__init__`.
 
     `absname` is an absolute module name of specified `name`
     (e.g. "hgext.convert"). This can be used to compose prefix for sub
     modules or so.
 
     `dottedpath` is a `dotted_name_of_path()`-ed source file path
     (e.g. "hgext.convert.__init__") of `name`. This is used to look
     module up in `localmods` again.
 
     `hassubmod` is whether it may have sub modules under it (for
     convenient, even though this is also equivalent to "absname !=
     dottednpath")
 
     >>> localmods = {'foo.__init__', 'foo.foo1',
     ...              'foo.bar.__init__', 'foo.bar.bar1',
     ...              'baz.__init__', 'baz.baz1'}
     >>> fromlocal = fromlocalfunc('foo.xxx', localmods)
     >>> # relative
     >>> fromlocal('foo1')
     ('foo.foo1', 'foo.foo1', False)
     >>> fromlocal('bar')
     ('foo.bar', 'foo.bar.__init__', True)
     >>> fromlocal('bar.bar1')
     ('foo.bar.bar1', 'foo.bar.bar1', False)
     >>> # absolute
     >>> fromlocal('baz')
     ('baz', 'baz.__init__', True)
     >>> fromlocal('baz.baz1')
     ('baz.baz1', 'baz.baz1', False)
     >>> # unknown = maybe standard library
     >>> fromlocal('os')
     False
     >>> fromlocal(None, 1)
     ('foo', 'foo.__init__', True)
     >>> fromlocal('foo1', 1)
     ('foo.foo1', 'foo.foo1', False)
     >>> fromlocal2 = fromlocalfunc('foo.xxx.yyy', localmods)
     >>> fromlocal2(None, 2)
     ('foo', 'foo.__init__', True)
     >>> fromlocal2('bar2', 1)
     False
     >>> fromlocal2('bar', 2)
     ('foo.bar', 'foo.bar.__init__', True)
     """
     if not isinstance(modulename, str):
         modulename = modulename.decode('ascii')
     prefix = '.'.join(modulename.split('.')[:-1])
     if prefix:
         prefix += '.'
+
     def fromlocal(name, level=0):
         # name is false value when relative imports are used.
         if not name:
             # If relative imports are used, level must not be absolute.
             assert level > 0
             candidates = ['.'.join(modulename.split('.')[:-level])]
         else:
             if not level:
                 # Check relative name first.
                 candidates = [prefix + name, name]
             else:
-                candidates = ['.'.join(modulename.split('.')[:-level]) +
-                              '.' + name]
+                candidates = [
+                    '.'.join(modulename.split('.')[:-level]) + '.' + name
+                ]
 
         for n in candidates:
             if n in localmods:
                 return (n, n, False)
             dottedpath = n + '.__init__'
             if dottedpath in localmods:
                 return (n, dottedpath, True)
         return False
+
     return fromlocal
 
+
 def populateextmods(localmods):
     """Populate C extension modules based on pure modules"""
     newlocalmods = set(localmods)
     for n in localmods:
         if n.startswith('mercurial.pure.'):
-            m = n[len('mercurial.pure.'):]
+            m = n[len('mercurial.pure.') :]
             newlocalmods.add('mercurial.cext.' + m)
             newlocalmods.add('mercurial.cffi._' + m)
     return newlocalmods
 
+
 def list_stdlib_modules():
     """List the modules present in the stdlib.
 
     >>> py3 = sys.version_info[0] >= 3
     >>> mods = set(list_stdlib_modules())
     >>> 'BaseHTTPServer' in mods or py3
     True
 
     os.path isn't really a module, so it's missing:
 
     >>> 'os.path' in mods
     False
 
     sys requires special treatment, because it's baked into the
     interpreter, but it should still appear:
 
     >>> 'sys' in mods
     True
 
     >>> 'collections' in mods
     True
 
     >>> 'cStringIO' in mods or py3
     True
 
     >>> 'cffi' in mods
     True
     """
     for m in sys.builtin_module_names:
         yield m
     # These modules only exist on windows, but we should always
     # consider them stdlib.
     for m in ['msvcrt', '_winreg']:
         yield m
     yield '__builtin__'
-    yield 'builtins' # python3 only
-    yield 'importlib.abc' # python3 only
-    yield 'importlib.machinery' # python3 only
-    yield 'importlib.util' # python3 only
+    yield 'builtins'  # python3 only
+    yield 'importlib.abc'  # python3 only
+    yield 'importlib.machinery'  # python3 only
+    yield 'importlib.util'  # python3 only
     for m in 'fcntl', 'grp', 'pwd', 'termios':  # Unix only
         yield m
-    for m in 'cPickle', 'datetime': # in Python (not C) on PyPy
+    for m in 'cPickle', 'datetime':  # in Python (not C) on PyPy
         yield m
     for m in ['cffi']:
         yield m
     stdlib_prefixes = {sys.prefix, sys.exec_prefix}
     # We need to supplement the list of prefixes for the search to work
     # when run from within a virtualenv.
     for mod in (basehttpserver, zlib):
         if mod is None:
             continue
         try:
             # Not all module objects have a __file__ attribute.
             filename = mod.__file__
         except AttributeError:
             continue
         dirname = os.path.dirname(filename)
         for prefix in stdlib_prefixes:
             if dirname.startswith(prefix):
                 # Then this directory is redundant.
                 break
         else:
             stdlib_prefixes.add(dirname)
     sourceroot = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
     for libpath in sys.path:
         # We want to walk everything in sys.path that starts with something in
         # stdlib_prefixes, but not directories from the hg sources.
-        if (os.path.abspath(libpath).startswith(sourceroot)
-            or not any(libpath.startswith(p) for p in stdlib_prefixes)):
+        if os.path.abspath(libpath).startswith(sourceroot) or not any(
+            libpath.startswith(p) for p in stdlib_prefixes
+        ):
             continue
         for top, dirs, files in os.walk(libpath):
             for i, d in reversed(list(enumerate(dirs))):
-                if (not os.path.exists(os.path.join(top, d, '__init__.py'))
-                    or top == libpath and d in ('hgdemandimport', 'hgext',
-                                                'mercurial')):
+                if (
+                    not os.path.exists(os.path.join(top, d, '__init__.py'))
+                    or top == libpath
+                    and d in ('hgdemandimport', 'hgext', 'mercurial')
+                ):
                     del dirs[i]
             for name in files:
                 if not name.endswith(('.py', '.so', '.pyc', '.pyo', '.pyd')):
                     continue
                 if name.startswith('__init__.py'):
                     full_path = top
                 else:
                     full_path = os.path.join(top, name)
-                rel_path = full_path[len(libpath) + 1:]
+                rel_path = full_path[len(libpath) + 1 :]
                 mod = dotted_name_of_path(rel_path)
                 yield mod
 
+
 stdlib_modules = set(list_stdlib_modules())
 
+
 def imported_modules(source, modulename, f, localmods, ignore_nested=False):
     """Given the source of a file as a string, yield the names
     imported by that file.
 
     Args:
       source: The python source to examine as a string.
       modulename: of specified python source (may have `__init__`)
       localmods: set of locally defined module names (may have `__init__`)
       ignore_nested: If true, import statements that do not start in
                      column zero will be ignored.
 
     Returns:
       A list of absolute module names imported by the given source.
 
     >>> f = 'foo/xxx.py'
     >>> modulename = 'foo.xxx'
     >>> localmods = {'foo.__init__': True,
     ...              'foo.foo1': True, 'foo.foo2': True,
     ...              'foo.bar.__init__': True, 'foo.bar.bar1': True,
     ...              'baz.__init__': True, 'baz.baz1': True }
     >>> # standard library (= not locally defined ones)
     >>> sorted(imported_modules(
     ...        'from stdlib1 import foo, bar; import stdlib2',
     ...        modulename, f, localmods))
     []
     >>> # relative importing
     >>> sorted(imported_modules(
     ...        'import foo1; from bar import bar1',
     ...        modulename, f, localmods))
     ['foo.bar.bar1', 'foo.foo1']
     >>> sorted(imported_modules(
     ...        'from bar.bar1 import name1, name2, name3',
     ...        modulename, f, localmods))
     ['foo.bar.bar1']
     >>> # absolute importing
     >>> sorted(imported_modules(
     ...        'from baz import baz1, name1',
     ...        modulename, f, localmods))
     ['baz.__init__', 'baz.baz1']
     >>> # mixed importing, even though it shouldn't be recommended
     >>> sorted(imported_modules(
     ...        'import stdlib, foo1, baz',
     ...        modulename, f, localmods))
     ['baz.__init__', 'foo.foo1']
     >>> # ignore_nested
     >>> sorted(imported_modules(
     ... '''import foo
     ... def wat():
     ...     import bar
     ... ''', modulename, f, localmods))
     ['foo.__init__', 'foo.bar.__init__']
     >>> sorted(imported_modules(
     ... '''import foo
     ... def wat():
     ...     import bar
     ... ''', modulename, f, localmods, ignore_nested=True))
     ['foo.__init__']
     """
     fromlocal = fromlocalfunc(modulename, localmods)
     for node in ast.walk(ast.parse(source, f)):
         if ignore_nested and getattr(node, 'col_offset', 0) > 0:
             continue
         if isinstance(node, ast.Import):
             for n in node.names:
                 found = fromlocal(n.name)
                 if not found:
                     # this should import standard library
                     continue
                 yield found[1]
         elif isinstance(node, ast.ImportFrom):
             found = fromlocal(node.module, node.level)
             if not found:
                 # this should import standard library
                 continue
 
             absname, dottedpath, hassubmod = found
             if not hassubmod:
                 # "dottedpath" is not a package; must be imported
                 yield dottedpath
                 # examination of "node.names" should be redundant
                 # e.g.: from mercurial.node import nullid, nullrev
                 continue
 
             modnotfound = False
             prefix = absname + '.'
             for n in node.names:
                 found = fromlocal(prefix + n.name)
                 if not found:
                     # this should be a function or a property of "node.module"
                     modnotfound = True
                     continue
                 yield found[1]
             if modnotfound:
                 # "dottedpath" is a package, but imported because of non-module
                 # lookup
                 yield dottedpath
 
+
 def verify_import_convention(module, source, localmods):
     """Verify imports match our established coding convention.
 
     We have 2 conventions: legacy and modern. The modern convention is in
     effect when using absolute imports.
 
     The legacy convention only looks for mixed imports. The modern convention
     is much more thorough.
     """
     root = ast.parse(source)
     absolute = usingabsolute(root)
 
     if absolute:
         return verify_modern_convention(module, root, localmods)
     else:
         return verify_stdlib_on_own_line(root)
 
+
 def verify_modern_convention(module, root, localmods, root_col_offset=0):
     """Verify a file conforms to the modern import convention rules.
 
     The rules of the modern convention are:
 
     * Ordering is stdlib followed by local imports. Each group is lexically
       sorted.
     * Importing multiple modules via "import X, Y" is not allowed: use
       separate import statements.
     * Importing multiple modules via "from X import ..." is allowed if using
       parenthesis and one entry per line.
     * Only 1 relative import statement per import level ("from .", "from ..")
       is allowed.
     * Relative imports from higher levels must occur before lower levels. e.g.
       "from .." must be before "from .".
     * Imports from peer packages should use relative import (e.g. do not
       "import mercurial.foo" from a "mercurial.*" module).
     * Symbols can only be imported from specific modules (see
       `allowsymbolimports`). For other modules, first import the module then
       assign the symbol to a module-level variable. In addition, these imports
       must be performed before other local imports. This rule only
       applies to import statements outside of any blocks.
     * Relative imports from the standard library are not allowed, unless that
       library is also a local module.
     * Certain modules must be aliased to alternate names to avoid aliasing
       and readability problems. See `requirealias`.
     """
     if not isinstance(module, str):
         module = module.decode('ascii')
     topmodule = module.split('.')[0]
     fromlocal = fromlocalfunc(module, localmods)
 
     # Whether a local/non-stdlib import has been performed.
     seenlocal = None
     # Whether a local/non-stdlib, non-symbol import has been seen.
     seennonsymbollocal = False
     # The last name to be imported (for sorting).
     lastname = None
     laststdlib = None
     # Relative import levels encountered so far.
     seenlevels = set()
 
     for node, newscope in walklocal(root):
+
         def msg(fmt, *args):
             return (fmt % args, node.lineno)
+
         if newscope:
             # Check for local imports in function
-            for r in verify_modern_convention(module, node, localmods,
-                                              node.col_offset + 4):
+            for r in verify_modern_convention(
+                module, node, localmods, node.col_offset + 4
+            ):
                 yield r
         elif isinstance(node, ast.Import):
             # Disallow "import foo, bar" and require separate imports
             # for each module.
             if len(node.names) > 1:
-                yield msg('multiple imported names: %s',
-                          ', '.join(n.name for n in node.names))
+                yield msg(
+                    'multiple imported names: %s',
+                    ', '.join(n.name for n in node.names),
+                )
 
             name = node.names[0].name
             asname = node.names[0].asname
 
             stdlib = name in stdlib_modules
 
             # Ignore sorting rules on imports inside blocks.
             if node.col_offset == root_col_offset:
                 if lastname and name < lastname and laststdlib == stdlib:
-                    yield msg('imports not lexically sorted: %s < %s',
-                              name, lastname)
+                    yield msg(
+                        'imports not lexically sorted: %s < %s', name, lastname
+                    )
 
             lastname = name
             laststdlib = stdlib
 
             # stdlib imports should be before local imports.
             if stdlib and seenlocal and node.col_offset == root_col_offset:
-                yield msg('stdlib import "%s" follows local import: %s',
-                          name, seenlocal)
+                yield msg(
+                    'stdlib import "%s" follows local import: %s',
+                    name,
+                    seenlocal,
+                )
 
             if not stdlib:
                 seenlocal = name
 
             # Import of sibling modules should use relative imports.
             topname = name.split('.')[0]
             if topname == topmodule:
                 yield msg('import should be relative: %s', name)
 
             if name in requirealias and asname != requirealias[name]:
-                yield msg('%s module must be "as" aliased to %s',
-                          name, requirealias[name])
+                yield msg(
+                    '%s module must be "as" aliased to %s',
+                    name,
+                    requirealias[name],
+                )
 
         elif isinstance(node, ast.ImportFrom):
             # Resolve the full imported module name.
             if node.level > 0:
-                fullname = '.'.join(module.split('.')[:-node.level])
+                fullname = '.'.join(module.split('.')[: -node.level])
                 if node.module:
                     fullname += '.%s' % node.module
             else:
                 assert node.module
                 fullname = node.module
 
                 topname = fullname.split('.')[0]
                 if topname == topmodule:
                     yield msg('import should be relative: %s', fullname)
 
             # __future__ is special since it needs to come first and use
             # symbol import.
             if fullname != '__future__':
                 if not fullname or (
                     fullname in stdlib_modules
                     and fullname not in localmods
-                    and fullname + '.__init__' not in localmods):
+                    and fullname + '.__init__' not in localmods
+                ):
                     yield msg('relative import of stdlib module')
                 else:
                     seenlocal = fullname
 
             # Direct symbol import is only allowed from certain modules and
             # must occur before non-symbol imports.
             found = fromlocal(node.module, node.level)
             if found and found[2]:  # node.module is a package
                 prefix = found[0] + '.'
-                symbols = (n.name for n in node.names
-                           if not fromlocal(prefix + n.name))
+                symbols = (
+                    n.name for n in node.names if not fromlocal(prefix + n.name)
+                )
             else:
                 symbols = (n.name for n in node.names)
             symbols = [sym for sym in symbols if sym not in directsymbols]
             if node.module and node.col_offset == root_col_offset:
                 if symbols and fullname not in allowsymbolimports:
-                    yield msg('direct symbol import %s from %s',
-                              ', '.join(symbols), fullname)
+                    yield msg(
+                        'direct symbol import %s from %s',
+                        ', '.join(symbols),
+                        fullname,
+                    )
 
                 if symbols and seennonsymbollocal:
-                    yield msg('symbol import follows non-symbol import: %s',
-                              fullname)
+                    yield msg(
+                        'symbol import follows non-symbol import: %s', fullname
+                    )
             if not symbols and fullname not in stdlib_modules:
                 seennonsymbollocal = True
 
             if not node.module:
                 assert node.level
 
                 # Only allow 1 group per level.
-                if (node.level in seenlevels
-                    and node.col_offset == root_col_offset):
-                    yield msg('multiple "from %s import" statements',
-                              '.' * node.level)
+                if (
+                    node.level in seenlevels
+                    and node.col_offset == root_col_offset
+                ):
+                    yield msg(
+                        'multiple "from %s import" statements', '.' * node.level
+                    )
 
                 # Higher-level groups come before lower-level groups.
                 if any(node.level > l for l in seenlevels):
-                    yield msg('higher-level import should come first: %s',
-                              fullname)
+                    yield msg(
+                        'higher-level import should come first: %s', fullname
+                    )
 
                 seenlevels.add(node.level)
 
             # Entries in "from .X import ( ... )" lists must be lexically
             # sorted.
             lastentryname = None
 
             for n in node.names:
                 if lastentryname and n.name < lastentryname:
-                    yield msg('imports from %s not lexically sorted: %s < %s',
-                              fullname, n.name, lastentryname)
+                    yield msg(
+                        'imports from %s not lexically sorted: %s < %s',
+                        fullname,
+                        n.name,
+                        lastentryname,
+                    )
 
                 lastentryname = n.name
 
                 if n.name in requirealias and n.asname != requirealias[n.name]:
-                    yield msg('%s from %s must be "as" aliased to %s',
-                              n.name, fullname, requirealias[n.name])
+                    yield msg(
+                        '%s from %s must be "as" aliased to %s',
+                        n.name,
+                        fullname,
+                        requirealias[n.name],
+                    )
+
 
 def verify_stdlib_on_own_line(root):
     """Given some python source, verify that stdlib imports are done
     in separate statements from relative local module imports.
 
     >>> list(verify_stdlib_on_own_line(ast.parse('import sys, foo')))
     [('mixed imports\\n   stdlib:    sys\\n   relative:  foo', 1)]
     >>> list(verify_stdlib_on_own_line(ast.parse('import sys, os')))
     []
     >>> list(verify_stdlib_on_own_line(ast.parse('import foo, bar')))
     []
     """
     for node in ast.walk(root):
         if isinstance(node, ast.Import):
             from_stdlib = {False: [], True: []}
             for n in node.names:
                 from_stdlib[n.name in stdlib_modules].append(n.name)
             if from_stdlib[True] and from_stdlib[False]:
-                yield ('mixed imports\n   stdlib:    %s\n   relative:  %s' %
-                       (', '.join(sorted(from_stdlib[True])),
-                        ', '.join(sorted(from_stdlib[False]))), node.lineno)
+                yield (
+                    'mixed imports\n   stdlib:    %s\n   relative:  %s'
+                    % (
+                        ', '.join(sorted(from_stdlib[True])),
+                        ', '.join(sorted(from_stdlib[False])),
+                    ),
+                    node.lineno,
+                )
+
 
 class CircularImport(Exception):
     pass
 
+
 def checkmod(mod, imports):
     shortest = {}
     visit = [[mod]]
     while visit:
         path = visit.pop(0)
         for i in sorted(imports.get(path[-1], [])):
             if len(path) < shortest.get(i, 1000):
                 shortest[i] = len(path)
                 if i in path:
                     if i == path[0]:
                         raise CircularImport(path)
                     continue
                 visit.append(path + [i])
 
+
 def rotatecycle(cycle):
     """arrange a cycle so that the lexicographically first module listed first
 
     >>> rotatecycle(['foo', 'bar'])
     ['bar', 'foo', 'bar']
     """
     lowest = min(cycle)
     idx = cycle.index(lowest)
     return cycle[idx:] + cycle[:idx] + [lowest]
 
+
 def find_cycles(imports):
     """Find cycles in an already-loaded import graph.
 
     All module names recorded in `imports` should be absolute one.
 
     >>> from __future__ import print_function
     >>> imports = {'top.foo': ['top.bar', 'os.path', 'top.qux'],
     ...            'top.bar': ['top.baz', 'sys'],
     ...            'top.baz': ['top.foo'],
     ...            'top.qux': ['top.foo']}
     >>> print('\\n'.join(sorted(find_cycles(imports))))
     top.bar -> top.baz -> top.foo -> top.bar
     top.foo -> top.qux -> top.foo
     """
     cycles = set()
     for mod in sorted(imports.keys()):
         try:
             checkmod(mod, imports)
         except CircularImport as e:
             cycle = e.args[0]
             cycles.add(" -> ".join(rotatecycle(cycle)))
     return cycles
 
+
 def _cycle_sortkey(c):
     return len(c), c
 
+
 def embedded(f, modname, src):
     """Extract embedded python code
 
     >>> def _forcestr(thing):
     ...     if not isinstance(thing, str):
     ...         return thing.decode('ascii')
     ...     return thing
     >>> def test(fn, lines):
     ...     for s, m, f, l in embedded(fn, b"example", lines):
     ...         print("%s %s %d" % (_forcestr(m), _forcestr(f), l))
     ...         print(repr(_forcestr(s)))
     >>> lines = [
     ...   'comment',
     ...   '  >>> from __future__ import print_function',
     ...   "  >>> ' multiline",
     ...   "  ... string'",
     ...   '  ',
     ...   'comment',
     ...   '  $ cat > foo.py <<EOF',
     ...   '  > from __future__ import print_function',
     ...   '  > EOF',
     ... ]
     >>> test(b"example.t", lines)
     example[2] doctest.py 1
     "from __future__ import print_function\\n' multiline\\nstring'\\n\\n"
     example[8] foo.py 7
     'from __future__ import print_function\\n'
     """
     errors = []
     for name, starts, ends, code in testparseutil.pyembedded(f, src, errors):
         if not name:
             # use 'doctest.py', in order to make already existing
             # doctest above pass instantly
             name = 'doctest.py'
         # "starts" is "line number" (1-origin), but embedded() is
         # expected to return "line offset" (0-origin). Therefore, this
         # yields "starts - 1".
         if not isinstance(modname, str):
             modname = modname.decode('utf8')
         yield code, "%s[%d]" % (modname, starts), name, starts - 1
 
+
 def sources(f, modname):
     """Yields possibly multiple sources from a filepath
 
     input: filepath, modulename
     yields:  script(string), modulename, filepath, linenumber
 
     For embedded scripts, the modulename and filepath will be different
     from the function arguments. linenumber is an offset relative to
     the input file.
     """
     py = False
     if not f.endswith('.t'):
         with open(f, 'rb') as src:
             yield src.read(), modname, f, 0
             py = True
     if py or f.endswith('.t'):
         with open(f, 'r') as src:
             for script, modname, t, line in embedded(f, modname, src):
                 yield script, modname.encode('utf8'), t, line
 
+
 def main(argv):
     if len(argv) < 2 or (argv[1] == '-' and len(argv) > 2):
         print('Usage: %s {-|file [file] [file] ...}')
         return 1
     if argv[1] == '-':
         argv = argv[:1]
         argv.extend(l.rstrip() for l in sys.stdin.readlines())
     localmodpaths = {}
     used_imports = {}
     any_errors = False
     for source_path in argv[1:]:
         modname = dotted_name_of_path(source_path)
         localmodpaths[modname] = source_path
     localmods = populateextmods(localmodpaths)
     for localmodname, source_path in sorted(localmodpaths.items()):
         if not isinstance(localmodname, bytes):
             # This is only safe because all hg's files are ascii
             localmodname = localmodname.encode('ascii')
         for src, modname, name, line in sources(source_path, localmodname):
             try:
                 used_imports[modname] = sorted(
-                    imported_modules(src, modname, name, localmods,
-                                     ignore_nested=True))
-                for error, lineno in verify_import_convention(modname, src,
-                                                              localmods):
+                    imported_modules(
+                        src, modname, name, localmods, ignore_nested=True
+                    )
+                )
+                for error, lineno in verify_import_convention(
+                    modname, src, localmods
+                ):
                     any_errors = True
                     print('%s:%d: %s' % (source_path, lineno + line, error))
             except SyntaxError as e:
-                print('%s:%d: SyntaxError: %s' %
-                      (source_path, e.lineno + line, e))
+                print(
+                    '%s:%d: SyntaxError: %s' % (source_path, e.lineno + line, e)
+                )
     cycles = find_cycles(used_imports)
     if cycles:
         firstmods = set()
         for c in sorted(cycles, key=_cycle_sortkey):
             first = c.split()[0]
             # As a rough cut, ignore any cycle that starts with the
             # same module as some other cycle. Otherwise we see lots
             # of cycles that are effectively duplicates.
             if first in firstmods:
                 continue
             print('Import cycle:', c)
             firstmods.add(first)
         any_errors = True
     return any_errors != 0
 
+
 if __name__ == '__main__':
     sys.exit(int(main(sys.argv)))

mercurial/cacheutil.py

@@ -1,21 +1,22 b''
 # scmutil.py - Mercurial core utility functions
 #
 #  Copyright Matt Mackall <[e-mail]> and other
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 from __future__ import absolute_import
 
 from . import repoview
 
+
 def cachetocopy(srcrepo):
     """return the list of cache file valuable to copy during a clone"""
     # In local clones we're copying all nodes, not just served
     # ones. Therefore copy all branch caches over.
     cachefiles = ['branch2']
     cachefiles += ['branch2-%s' % f for f in repoview.filtertable]
     cachefiles += ['rbc-names-v1', 'rbc-revs-v1']
     cachefiles += ['tags2']
     cachefiles += ['tags2-%s' % f for f in repoview.filtertable]
     cachefiles += ['hgtagsfnodes1']
     return cachefiles

mercurial/diffhelper.py

@@ -1,78 +1,81 b''
 # diffhelper.py - helper routines for patch
 #
 # Copyright 2009 Matt 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.
 
 from __future__ import absolute_import
 
 from .i18n import _
 
 from . import (
     error,
     pycompat,
 )
 
+
 def addlines(fp, hunk, lena, lenb, a, b):
     """Read lines from fp into the hunk
 
     The hunk is parsed into two arrays, a and b. a gets the old state of
     the text, b gets the new state. The control char from the hunk is saved
     when inserting into a, but not b (for performance while deleting files.)
     """
     while True:
         todoa = lena - len(a)
         todob = lenb - len(b)
         num = max(todoa, todob)
         if num == 0:
             break
         for i in pycompat.xrange(num):
             s = fp.readline()
             if not s:
                 raise error.ParseError(_('incomplete hunk'))
             if s == "\\ No newline at end of file\n":
                 fixnewline(hunk, a, b)
                 continue
             if s == '\n' or s == '\r\n':
                 # Some patches may be missing the control char
                 # on empty lines. Supply a leading space.
                 s = ' ' + s
             hunk.append(s)
             if s.startswith('+'):
                 b.append(s[1:])
             elif s.startswith('-'):
                 a.append(s)
             else:
                 b.append(s[1:])
                 a.append(s)
 
+
 def fixnewline(hunk, a, b):
     """Fix up the last lines of a and b when the patch has no newline at EOF"""
     l = hunk[-1]
     # tolerate CRLF in last line
     if l.endswith('\r\n'):
         hline = l[:-2]
     else:
         hline = l[:-1]
 
     if hline.startswith((' ', '+')):
         b[-1] = hline[1:]
     if hline.startswith((' ', '-')):
         a[-1] = hline
     hunk[-1] = hline
 
+
 def testhunk(a, b, bstart):
     """Compare the lines in a with the lines in b
 
     a is assumed to have a control char at the start of each line, this char
     is ignored in the compare.
     """
     alen = len(a)
     blen = len(b)
     if alen > blen - bstart or bstart < 0:
         return False
     for i in pycompat.xrange(alen):
         if a[i][1:] != b[i + bstart]:
             return False
     return True

mercurial/dirstateguard.py

@@ -1,75 +1,84 b''
 # dirstateguard.py - class to allow restoring dirstate after failure
 #
 # Copyright 2005-2007 Matt Mackall <[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.
 
 from __future__ import absolute_import
 
 from .i18n import _
 
 from . import (
     error,
     narrowspec,
     util,
 )
 
+
 class dirstateguard(util.transactional):
     '''Restore dirstate at unexpected failure.
 
     At the construction, this class does:
 
     - write current ``repo.dirstate`` out, and
     - save ``.hg/dirstate`` into the backup file
 
     This restores ``.hg/dirstate`` from backup file, if ``release()``
     is invoked before ``close()``.
 
     This just removes the backup file at ``close()`` before ``release()``.
     '''
 
     def __init__(self, repo, name):
         self._repo = repo
         self._active = False
         self._closed = False
         self._backupname = 'dirstate.backup.%s.%d' % (name, id(self))
-        self._narrowspecbackupname = ('narrowspec.backup.%s.%d' %
-                                      (name, id(self)))
+        self._narrowspecbackupname = 'narrowspec.backup.%s.%d' % (
+            name,
+            id(self),
+        )
         repo.dirstate.savebackup(repo.currenttransaction(), self._backupname)
         narrowspec.savewcbackup(repo, self._narrowspecbackupname)
         self._active = True
 
     def __del__(self):
-        if self._active: # still active
+        if self._active:  # still active
             # this may occur, even if this class is used correctly:
             # for example, releasing other resources like transaction
             # may raise exception before ``dirstateguard.release`` in
             # ``release(tr, ....)``.
             self._abort()
 
     def close(self):
-        if not self._active: # already inactivated
-            msg = (_("can't close already inactivated backup: %s")
-                   % self._backupname)
+        if not self._active:  # already inactivated
+            msg = (
+                _("can't close already inactivated backup: %s")
+                % self._backupname
+            )
             raise error.Abort(msg)
 
-        self._repo.dirstate.clearbackup(self._repo.currenttransaction(),
-                                         self._backupname)
+        self._repo.dirstate.clearbackup(
+            self._repo.currenttransaction(), self._backupname
+        )
         narrowspec.clearwcbackup(self._repo, self._narrowspecbackupname)
         self._active = False
         self._closed = True
 
     def _abort(self):
         narrowspec.restorewcbackup(self._repo, self._narrowspecbackupname)
-        self._repo.dirstate.restorebackup(self._repo.currenttransaction(),
-                                           self._backupname)
+        self._repo.dirstate.restorebackup(
+            self._repo.currenttransaction(), self._backupname
+        )
         self._active = False
 
     def release(self):
         if not self._closed:
-            if not self._active: # already inactivated
-                msg = (_("can't release already inactivated backup: %s")
-                       % self._backupname)
+            if not self._active:  # already inactivated
+                msg = (
+                    _("can't release already inactivated backup: %s")
+                    % self._backupname
+                )
                 raise error.Abort(msg)
             self._abort()

mercurial/httpconnection.py

@@ -1,121 +1,131 b''
 # httpconnection.py - urllib2 handler for new http support
 #
 # Copyright 2005, 2006, 2007, 2008 Matt Mackall <[e-mail]>
 # Copyright 2006, 2007 Alexis S. L. Carvalho <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 # Copyright 2011 Google, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import os
 
 from .i18n import _
 from . import (
     pycompat,
     util,
 )
 
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 # moved here from url.py to avoid a cycle
 class httpsendfile(object):
     """This is a wrapper around the objects returned by python's "open".
 
     Its purpose is to send file-like objects via HTTP.
     It do however not define a __len__ attribute because the length
     might be more than Py_ssize_t can handle.
     """
 
     def __init__(self, ui, *args, **kwargs):
         self.ui = ui
         self._data = open(*args, **kwargs)
         self.seek = self._data.seek
         self.close = self._data.close
         self.write = self._data.write
         self.length = os.fstat(self._data.fileno()).st_size
         self._pos = 0
         # We pass double the max for total because we currently have
         # to send the bundle twice in the case of a server that
         # requires authentication. Since we can't know until we try
         # once whether authentication will be required, just lie to
         # the user and maybe the push succeeds suddenly at 50%.
-        self._progress = ui.makeprogress(_('sending'), unit=_('kb'),
-                                         total=(self.length // 1024 * 2))
+        self._progress = ui.makeprogress(
+            _('sending'), unit=_('kb'), total=(self.length // 1024 * 2)
+        )
 
     def read(self, *args, **kwargs):
         ret = self._data.read(*args, **kwargs)
         if not ret:
             self._progress.complete()
             return ret
         self._pos += len(ret)
         self._progress.update(self._pos // 1024)
         return ret
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         self.close()
 
+
 # moved here from url.py to avoid a cycle
 def readauthforuri(ui, uri, user):
     uri = pycompat.bytesurl(uri)
     # Read configuration
     groups = {}
     for key, val in ui.configitems('auth'):
         if key in ('cookiefile',):
             continue
 
         if '.' not in key:
             ui.warn(_("ignoring invalid [auth] key '%s'\n") % key)
             continue
         group, setting = key.rsplit('.', 1)
         gdict = groups.setdefault(group, {})
         if setting in ('username', 'cert', 'key'):
             val = util.expandpath(val)
         gdict[setting] = val
 
     # Find the best match
     scheme, hostpath = uri.split('://', 1)
     bestuser = None
     bestlen = 0
     bestauth = None
     for group, auth in groups.iteritems():
         if user and user != auth.get('username', user):
             # If a username was set in the URI, the entry username
             # must either match it or be unset
             continue
         prefix = auth.get('prefix')
         if not prefix:
             continue
 
         prefixurl = util.url(prefix)
         if prefixurl.user and prefixurl.user != user:
             # If a username was set in the prefix, it must match the username in
             # the URI.
             continue
 
         # The URI passed in has been stripped of credentials, so erase the user
         # here to allow simpler matching.
         prefixurl.user = None
         prefix = bytes(prefixurl)
 
         p = prefix.split('://', 1)
         if len(p) > 1:
             schemes, prefix = [p[0]], p[1]
         else:
             schemes = (auth.get('schemes') or 'https').split()
-        if ((prefix == '*' or hostpath.startswith(prefix)) and
-            (len(prefix) > bestlen or (len(prefix) == bestlen and
-                                       not bestuser and 'username' in auth))
-            and scheme in schemes):
+        if (
+            (prefix == '*' or hostpath.startswith(prefix))
+            and (
+                len(prefix) > bestlen
+                or (
+                    len(prefix) == bestlen
+                    and not bestuser
+                    and 'username' in auth
+                )
+            )
+            and scheme in schemes
+        ):
             bestlen = len(prefix)
             bestauth = group, auth
             bestuser = auth.get('username')
             if user and not bestuser:
                 auth['username'] = user
     return bestauth

mercurial/minifileset.py

@@ -1,92 +1,100 b''
 # minifileset.py - a simple language to select files
 #
 # Copyright 2017 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 from .i18n import _
 from . import (
     error,
     fileset,
     filesetlang,
     pycompat,
 )
 
+
 def _sizep(x):
     # i18n: "size" is a keyword
     expr = filesetlang.getstring(x, _("size requires an expression"))
     return fileset.sizematcher(expr)
 
+
 def _compile(tree):
     if not tree:
         raise error.ParseError(_("missing argument"))
     op = tree[0]
     if op == 'withstatus':
         return _compile(tree[1])
     elif op in {'symbol', 'string', 'kindpat'}:
         name = filesetlang.getpattern(tree, {'path'}, _('invalid file pattern'))
-        if name.startswith('**'): # file extension test, ex. "**.tar.gz"
+        if name.startswith('**'):  # file extension test, ex. "**.tar.gz"
             ext = name[2:]
             for c in pycompat.bytestr(ext):
                 if c in '*{}[]?/\\':
                     raise error.ParseError(_('reserved character: %s') % c)
             return lambda n, s: n.endswith(ext)
-        elif name.startswith('path:'): # directory or full path test
-            p = name[5:] # prefix
+        elif name.startswith('path:'):  # directory or full path test
+            p = name[5:]  # prefix
             pl = len(p)
-            f = lambda n, s: n.startswith(p) and (len(n) == pl
-                                                  or n[pl:pl + 1] == '/')
+            f = lambda n, s: n.startswith(p) and (
+                len(n) == pl or n[pl : pl + 1] == '/'
+            )
             return f
-        raise error.ParseError(_("unsupported file pattern: %s") % name,
-                               hint=_('paths must be prefixed with "path:"'))
+        raise error.ParseError(
+            _("unsupported file pattern: %s") % name,
+            hint=_('paths must be prefixed with "path:"'),
+        )
     elif op in {'or', 'patterns'}:
         funcs = [_compile(x) for x in tree[1:]]
         return lambda n, s: any(f(n, s) for f in funcs)
     elif op == 'and':
         func1 = _compile(tree[1])
         func2 = _compile(tree[2])
         return lambda n, s: func1(n, s) and func2(n, s)
     elif op == 'not':
         return lambda n, s: not _compile(tree[1])(n, s)
     elif op == 'func':
         symbols = {
             'all': lambda n, s: True,
             'none': lambda n, s: False,
             'size': lambda n, s: _sizep(tree[2])(s),
         }
 
         name = filesetlang.getsymbol(tree[1])
         if name in symbols:
             return symbols[name]
 
         raise error.UnknownIdentifier(name, symbols.keys())
-    elif op == 'minus':     # equivalent to 'x and not y'
+    elif op == 'minus':  # equivalent to 'x and not y'
         func1 = _compile(tree[1])
         func2 = _compile(tree[2])
         return lambda n, s: func1(n, s) and not func2(n, s)
     elif op == 'list':
-        raise error.ParseError(_("can't use a list in this context"),
-                               hint=_('see \'hg help "filesets.x or y"\''))
+        raise error.ParseError(
+            _("can't use a list in this context"),
+            hint=_('see \'hg help "filesets.x or y"\''),
+        )
     raise error.ProgrammingError('illegal tree: %r' % (tree,))
 
+
 def compile(text):
     """generate a function (path, size) -> bool from filter specification.
 
     "text" could contain the operators defined by the fileset language for
     common logic operations, and parenthesis for grouping.  The supported path
     tests are '**.extname' for file extension test, and '"path:dir/subdir"'
     for prefix test.  The ``size()`` predicate is borrowed from filesets to test
     file size.  The predicates ``all()`` and ``none()`` are also supported.
 
     '(**.php & size(">10MB")) | **.zip | (path:bin & !path:bin/README)' for
     example, will catch all php files whose size is greater than 10 MB, all
     files whose name ends with ".zip", and all files under "bin" in the repo
     root except for "bin/README".
     """
     tree = filesetlang.parse(text)
     tree = filesetlang.analyze(tree)
     tree = filesetlang.optimize(tree)
     return _compile(tree)

mercurial/node.py

@@ -1,47 +1,49 b''
 # node.py - basic nodeid manipulation for mercurial
 #
 # Copyright 2005, 2006 Matt Mackall <[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.
 
 from __future__ import absolute_import
 
 import binascii
 
 # This ugly style has a noticeable effect in manifest parsing
 hex = binascii.hexlify
 # Adapt to Python 3 API changes. If this ends up showing up in
 # profiles, we can use this version only on Python 3, and forward
 # binascii.unhexlify like we used to on Python 2.
 def bin(s):
     try:
         return binascii.unhexlify(s)
     except binascii.Error as e:
         raise TypeError(e)
 
+
 nullrev = -1
 # In hex, this is '0000000000000000000000000000000000000000'
 nullid = b"\0" * 20
 nullhex = hex(nullid)
 
 # Phony node value to stand-in for new files in some uses of
 # manifests.
 # In hex, this is '2121212121212121212121212121212121212121'
 newnodeid = '!!!!!!!!!!!!!!!!!!!!'
 # In hex, this is '3030303030303030303030303030306164646564'
 addednodeid = '000000000000000added'
 # In hex, this is '3030303030303030303030306d6f646966696564'
 modifiednodeid = '000000000000modified'
 
 wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid}
 
 # pseudo identifiers for working directory
 # (they are experimental, so don't add too many dependencies on them)
-wdirrev = 0x7fffffff
+wdirrev = 0x7FFFFFFF
 # In hex, this is 'ffffffffffffffffffffffffffffffffffffffff'
 wdirid = b"\xff" * 20
 wdirhex = hex(wdirid)
 
+
 def short(node):
     return hex(node[:6])

mercurial/policy.py

@@ -1,146 +1,155 b''
 # policy.py - module policy logic for Mercurial.
 #
 # Copyright 2015 Gregory Szorc <[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.
 
 from __future__ import absolute_import
 
 import os
 import sys
 
 # Rules for how modules can be loaded. Values are:
 #
 #    c - require C extensions
 #    rust+c - require Rust and C extensions
 #    rust+c-allow - allow Rust and C extensions with fallback to pure Python
 #                   for each
 #    allow - allow pure Python implementation when C loading fails
 #    cffi - required cffi versions (implemented within pure module)
 #    cffi-allow - allow pure Python implementation if cffi version is missing
 #    py - only load pure Python modules
 #
 # By default, fall back to the pure modules so the in-place build can
 # run without recompiling the C extensions. This will be overridden by
 # __modulepolicy__ generated by setup.py.
 policy = b'allow'
 _packageprefs = {
     # policy: (versioned package, pure package)
     b'c': (r'cext', None),
     b'allow': (r'cext', r'pure'),
     b'cffi': (r'cffi', None),
     b'cffi-allow': (r'cffi', r'pure'),
     b'py': (None, r'pure'),
     # For now, rust policies impact importrust only
     b'rust+c': (r'cext', None),
     b'rust+c-allow': (r'cext', r'pure'),
 }
 
 try:
     from . import __modulepolicy__
+
     policy = __modulepolicy__.modulepolicy
 except ImportError:
     pass
 
 # PyPy doesn't load C extensions.
 #
 # The canonical way to do this is to test platform.python_implementation().
 # But we don't import platform and don't bloat for it here.
 if r'__pypy__' in sys.builtin_module_names:
     policy = b'cffi'
 
 # Environment variable can always force settings.
 if sys.version_info[0] >= 3:
     if r'HGMODULEPOLICY' in os.environ:
         policy = os.environ[r'HGMODULEPOLICY'].encode(r'utf-8')
 else:
     policy = os.environ.get(r'HGMODULEPOLICY', policy)
 
+
 def _importfrom(pkgname, modname):
     # from .<pkgname> import <modname> (where . is looked through this module)
     fakelocals = {}
     pkg = __import__(pkgname, globals(), fakelocals, [modname], level=1)
     try:
         fakelocals[modname] = mod = getattr(pkg, modname)
     except AttributeError:
         raise ImportError(r'cannot import name %s' % modname)
     # force import; fakelocals[modname] may be replaced with the real module
     getattr(mod, r'__doc__', None)
     return fakelocals[modname]
 
+
 # keep in sync with "version" in C modules
 _cextversions = {
     (r'cext', r'base85'): 1,
     (r'cext', r'bdiff'): 3,
     (r'cext', r'mpatch'): 1,
     (r'cext', r'osutil'): 4,
     (r'cext', r'parsers'): 13,
 }
 
 # map import request to other package or module
 _modredirects = {
     (r'cext', r'charencode'): (r'cext', r'parsers'),
     (r'cffi', r'base85'): (r'pure', r'base85'),
     (r'cffi', r'charencode'): (r'pure', r'charencode'),
     (r'cffi', r'parsers'): (r'pure', r'parsers'),
 }
 
+
 def _checkmod(pkgname, modname, mod):
     expected = _cextversions.get((pkgname, modname))
     actual = getattr(mod, r'version', None)
     if actual != expected:
-        raise ImportError(r'cannot import module %s.%s '
-                          r'(expected version: %d, actual: %r)'
-                          % (pkgname, modname, expected, actual))
+        raise ImportError(
+            r'cannot import module %s.%s '
+            r'(expected version: %d, actual: %r)'
+            % (pkgname, modname, expected, actual)
+        )
+
 
 def importmod(modname):
     """Import module according to policy and check API version"""
     try:
         verpkg, purepkg = _packageprefs[policy]
     except KeyError:
         raise ImportError(r'invalid HGMODULEPOLICY %r' % policy)
     assert verpkg or purepkg
     if verpkg:
         pn, mn = _modredirects.get((verpkg, modname), (verpkg, modname))
         try:
             mod = _importfrom(pn, mn)
             if pn == verpkg:
                 _checkmod(pn, mn, mod)
             return mod
         except ImportError:
             if not purepkg:
                 raise
     pn, mn = _modredirects.get((purepkg, modname), (purepkg, modname))
     return _importfrom(pn, mn)
 
+
 def _isrustpermissive():
     """Assuming the policy is a Rust one, tell if it's permissive."""
     return policy.endswith(b'-allow')
 
+
 def importrust(modname, member=None, default=None):
     """Import Rust module according to policy and availability.
 
     If policy isn't a Rust one, this returns `default`.
 
     If either the module or its member is not available, this returns `default`
     if policy is permissive and raises `ImportError` if not.
     """
     if not policy.startswith(b'rust'):
         return default
 
     try:
         mod = _importfrom(r'rustext', modname)
     except ImportError:
         if _isrustpermissive():
             return default
         raise
     if member is None:
         return mod
 
     try:
         return getattr(mod, member)
     except AttributeError:
         if _isrustpermissive():
             return default
         raise ImportError(r"Cannot import name %s" % member)

mercurial/pushkey.py

@@ -1,61 +1,71 b''
 # pushkey.py - dispatching for pushing and pulling keys
 #
 # Copyright 2010 Matt Mackall <[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.
 
 from __future__ import absolute_import
 
 from . import (
     bookmarks,
     encoding,
     obsolete,
     phases,
 )
 
+
 def _nslist(repo):
     n = {}
     for k in _namespaces:
         n[k] = ""
     if not obsolete.isenabled(repo, obsolete.exchangeopt):
         n.pop('obsolete')
     return n
 
-_namespaces = {"namespaces": (lambda *x: False, _nslist),
-               "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
-               "phases": (phases.pushphase, phases.listphases),
-               "obsolete": (obsolete.pushmarker, obsolete.listmarkers),
-              }
+
+_namespaces = {
+    "namespaces": (lambda *x: False, _nslist),
+    "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
+    "phases": (phases.pushphase, phases.listphases),
+    "obsolete": (obsolete.pushmarker, obsolete.listmarkers),
+}
+
 
 def register(namespace, pushkey, listkeys):
     _namespaces[namespace] = (pushkey, listkeys)
 
+
 def _get(namespace):
     return _namespaces.get(namespace, (lambda *x: False, lambda *x: {}))
 
+
 def push(repo, namespace, key, old, new):
     '''should succeed iff value was old'''
     pk = _get(namespace)[0]
     return pk(repo, key, old, new)
 
+
 def list(repo, namespace):
     '''return a dict'''
     lk = _get(namespace)[1]
     return lk(repo)
 
+
 encode = encoding.fromlocal
 
 decode = encoding.tolocal
 
+
 def encodekeys(keys):
     """encode the content of a pushkey namespace for exchange over the wire"""
     return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys])
 
+
 def decodekeys(data):
     """decode the content of a pushkey namespace from exchange over the wire"""
     result = {}
     for l in data.splitlines():
         k, v = l.split('\t')
         result[decode(k)] = decode(v)
     return result

mercurial/rcutil.py

@@ -1,99 +1,105 b''
 # rcutil.py - utilities about config paths, special config sections etc.
 #
 #  Copyright Mercurial Contributors
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import os
 
 from . import (
     encoding,
     pycompat,
     util,
 )
 
 if pycompat.iswindows:
     from . import scmwindows as scmplatform
 else:
     from . import scmposix as scmplatform
 
 fallbackpager = scmplatform.fallbackpager
 systemrcpath = scmplatform.systemrcpath
 userrcpath = scmplatform.userrcpath
 
+
 def _expandrcpath(path):
     '''path could be a file or a directory. return a list of file paths'''
     p = util.expandpath(path)
     if os.path.isdir(p):
         join = os.path.join
-        return sorted(join(p, f) for f, k in util.listdir(p)
-                      if f.endswith('.rc'))
+        return sorted(
+            join(p, f) for f, k in util.listdir(p) if f.endswith('.rc')
+        )
     return [p]
 
+
 def envrcitems(env=None):
     '''Return [(section, name, value, source)] config items.
 
     The config items are extracted from environment variables specified by env,
     used to override systemrc, but not userrc.
 
     If env is not provided, encoding.environ will be used.
     '''
     if env is None:
         env = encoding.environ
     checklist = [
         ('EDITOR', 'ui', 'editor'),
         ('VISUAL', 'ui', 'editor'),
         ('PAGER', 'pager', 'pager'),
     ]
     result = []
     for envname, section, configname in checklist:
         if envname not in env:
             continue
         result.append((section, configname, env[envname], '$%s' % envname))
     return result
 
+
 def defaultrcpath():
     '''return rc paths in default.d'''
     path = []
     defaultpath = os.path.join(util.datapath, 'default.d')
     if os.path.isdir(defaultpath):
         path = _expandrcpath(defaultpath)
     return path
 
+
 def rccomponents():
     '''return an ordered [(type, obj)] about where to load configs.
 
     respect $HGRCPATH. if $HGRCPATH is empty, only .hg/hgrc of current repo is
     used. if $HGRCPATH is not set, the platform default will be used.
 
     if a directory is provided, *.rc files under it will be used.
 
     type could be either 'path' or 'items', if type is 'path', obj is a string,
     and is the config file path. if type is 'items', obj is a list of (section,
     name, value, source) that should fill the config directly.
     '''
     envrc = ('items', envrcitems())
 
     if 'HGRCPATH' in encoding.environ:
         # assume HGRCPATH is all about user configs so environments can be
         # overridden.
         _rccomponents = [envrc]
         for p in encoding.environ['HGRCPATH'].split(pycompat.ospathsep):
             if not p:
                 continue
             _rccomponents.extend(('path', p) for p in _expandrcpath(p))
     else:
         normpaths = lambda paths: [('path', os.path.normpath(p)) for p in paths]
         _rccomponents = normpaths(defaultrcpath() + systemrcpath())
         _rccomponents.append(envrc)
         _rccomponents.extend(normpaths(userrcpath()))
     return _rccomponents
 
+
 def defaultpagerenv():
     '''return a dict of default environment variables and their values,
     intended to be set before starting a pager.
     '''
     return {'LESS': 'FRX', 'LV': '-c'}

mercurial/rewriteutil.py

@@ -1,53 +1,55 b''
 # rewriteutil.py - utility functions for rewriting changesets
 #
 # Copyright 2017 Octobus <[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.
 
 from __future__ import absolute_import
 
 from .i18n import _
 
 from . import (
     error,
     node,
     obsolete,
     revset,
 )
 
+
 def precheck(repo, revs, action='rewrite'):
     """check if revs can be rewritten
     action is used to control the error message.
 
     Make sure this function is called after taking the lock.
     """
     if node.nullrev in revs:
-        msg = _("cannot %s null changeset") % (action)
+        msg = _("cannot %s null changeset") % action
         hint = _("no changeset checked out")
         raise error.Abort(msg, hint=hint)
 
     if len(repo[None].parents()) > 1:
         raise error.Abort(_("cannot %s while merging") % action)
 
     publicrevs = repo.revs('%ld and public()', revs)
     if publicrevs:
-        msg = _("cannot %s public changesets") % (action)
+        msg = _("cannot %s public changesets") % action
         hint = _("see 'hg help phases' for details")
         raise error.Abort(msg, hint=hint)
 
     newunstable = disallowednewunstable(repo, revs)
     if newunstable:
         raise error.Abort(_("cannot %s changeset with children") % action)
 
+
 def disallowednewunstable(repo, revs):
     """Checks whether editing the revs will create new unstable changesets and
     are we allowed to create them.
 
     To allow new unstable changesets, set the config:
         `experimental.evolution.allowunstable=True`
     """
     allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
     if allowunstable:
         return revset.baseset()
     return repo.revs("(%ld::) - %ld", revs, revs)

mercurial/scmposix.py

@@ -1,85 +1,96 b''
 from __future__ import absolute_import
 
 import array
 import errno
 import fcntl
 import os
 import sys
 
 from . import (
     encoding,
     pycompat,
     util,
 )
 
 # BSD 'more' escapes ANSI color sequences by default. This can be disabled by
 # $MORE variable, but there's no compatible option with Linux 'more'. Given
 # OS X is widely used and most modern Unix systems would have 'less', setting
 # 'less' as the default seems reasonable.
 fallbackpager = 'less'
 
+
 def _rcfiles(path):
     rcs = [os.path.join(path, 'hgrc')]
     rcdir = os.path.join(path, 'hgrc.d')
     try:
-        rcs.extend([os.path.join(rcdir, f)
-                    for f, kind in util.listdir(rcdir)
-                    if f.endswith(".rc")])
+        rcs.extend(
+            [
+                os.path.join(rcdir, f)
+                for f, kind in util.listdir(rcdir)
+                if f.endswith(".rc")
+            ]
+        )
     except OSError:
         pass
     return rcs
 
+
 def systemrcpath():
     path = []
     if pycompat.sysplatform == 'plan9':
         root = 'lib/mercurial'
     else:
         root = 'etc/mercurial'
     # old mod_python does not set sys.argv
     if len(getattr(sys, 'argv', [])) > 0:
         p = os.path.dirname(os.path.dirname(pycompat.sysargv[0]))
         if p != '/':
             path.extend(_rcfiles(os.path.join(p, root)))
     path.extend(_rcfiles('/' + root))
     return path
 
+
 def userrcpath():
     if pycompat.sysplatform == 'plan9':
         return [encoding.environ['home'] + '/lib/hgrc']
     elif pycompat.isdarwin:
         return [os.path.expanduser('~/.hgrc')]
     else:
         confighome = encoding.environ.get('XDG_CONFIG_HOME')
         if confighome is None or not os.path.isabs(confighome):
             confighome = os.path.expanduser('~/.config')
 
-        return [os.path.expanduser('~/.hgrc'),
-                os.path.join(confighome, 'hg', 'hgrc')]
+        return [
+            os.path.expanduser('~/.hgrc'),
+            os.path.join(confighome, 'hg', 'hgrc'),
+        ]
+
 
 def termsize(ui):
     try:
         import termios
+
         TIOCGWINSZ = termios.TIOCGWINSZ  # unavailable on IRIX (issue3449)
     except (AttributeError, ImportError):
         return 80, 24
 
     for dev in (ui.ferr, ui.fout, ui.fin):
         try:
             try:
                 fd = dev.fileno()
             except AttributeError:
                 continue
             if not os.isatty(fd):
                 continue
             arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8)
             height, width = array.array(r'h', arri)[:2]
             if width > 0 and height > 0:
                 return width, height
         except ValueError:
             pass
         except IOError as e:
             if e[0] == errno.EINVAL:
                 pass
             else:
                 raise
     return 80, 24

mercurial/scmwindows.py

@@ -1,61 +1,65 b''
 from __future__ import absolute_import
 
 import os
 
 from . import (
     encoding,
     pycompat,
     util,
     win32,
 )
 
 try:
     import _winreg as winreg
+
     winreg.CloseKey
 except ImportError:
     import winreg
 
 # MS-DOS 'more' is the only pager available by default on Windows.
 fallbackpager = 'more'
 
+
 def systemrcpath():
     '''return default os-specific hgrc search path'''
     rcpath = []
     filename = win32.executablepath()
     # Use mercurial.ini found in directory with hg.exe
     progrc = os.path.join(os.path.dirname(filename), 'mercurial.ini')
     rcpath.append(progrc)
     # Use hgrc.d found in directory with hg.exe
     progrcd = os.path.join(os.path.dirname(filename), 'hgrc.d')
     if os.path.isdir(progrcd):
         for f, kind in util.listdir(progrcd):
             if f.endswith('.rc'):
                 rcpath.append(os.path.join(progrcd, f))
     # else look for a system rcpath in the registry
-    value = util.lookupreg('SOFTWARE\\Mercurial', None,
-                           winreg.HKEY_LOCAL_MACHINE)
+    value = util.lookupreg(
+        'SOFTWARE\\Mercurial', None, winreg.HKEY_LOCAL_MACHINE
+    )
     if not isinstance(value, str) or not value:
         return rcpath
     value = util.localpath(value)
     for p in value.split(pycompat.ospathsep):
         if p.lower().endswith('mercurial.ini'):
             rcpath.append(p)
         elif os.path.isdir(p):
             for f, kind in util.listdir(p):
                 if f.endswith('.rc'):
                     rcpath.append(os.path.join(p, f))
     return rcpath
 
+
 def userrcpath():
     '''return os-specific hgrc search path to the user dir'''
     home = os.path.expanduser('~')
-    path = [os.path.join(home, 'mercurial.ini'),
-            os.path.join(home, '.hgrc')]
+    path = [os.path.join(home, 'mercurial.ini'), os.path.join(home, '.hgrc')]
     userprofile = encoding.environ.get('USERPROFILE')
     if userprofile and userprofile != home:
         path.append(os.path.join(userprofile, 'mercurial.ini'))
         path.append(os.path.join(userprofile, '.hgrc'))
     return path
 
+
 def termsize(ui):
     return win32.termsize()

mercurial/stack.py

@@ -1,23 +1,24 b''
 # stack.py - Mercurial functions for stack definition
 #
 #  Copyright Matt Mackall <[e-mail]> and other
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
+
 def getstack(repo, rev=None):
     """return a sorted smartrev of the stack containing either rev if it is
     not None or the current working directory parent.
 
     The stack will always contain all drafts changesets which are ancestors to
     the revision and are not merges.
     """
     if rev is None:
         rev = '.'
 
     revspec = 'only(%s) and not public() and not ::merge()'
     revisions = repo.revs(revspec, rev)
     revisions.sort()
     return revisions