rebase: 'hg pull --rebase' now update only if there was nothing to rebase
I recently discovered that 'hg pull --rebase' was also running an update. And it
was running it in all cases as long as the update would move the working copy
somewhere else...
This felt wrong and it actually is. This 'update' call is introduced in
92455c1d6f83. In that commit the intent is very clear. The update should happen
only when there was nothing to rebase. The implementation did not check if a
rebase was performed because, at that time, rebase would always leave you on the
top most changeset. Being on that top most changeset result in a no-op update
and the step was skipped.
However
9c78ed396075f changed rebase behavior to preserve the working copy
parent, so if we are not on a head at pull time, the code performs both a rebase
and an update.
This changeset introduce a test for this case and restore the intended behavior.
There are other issues with this custom update code but they will be addressed
in later changeset (eg: own destination logic, lack of heads warning).
I'm not super happy with the explicitly comparison 'rebase(...) == 1' but a
later series will have a cleaner way to handle it anyway (while making 'rebase'
pick its default destination like 'merge').
# parser.py - simple top-down operator precedence parser for mercurial
#
# Copyright 2010 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
# see http://effbot.org/zone/simple-top-down-parsing.htm and
# http://eli.thegreenplace.net/2010/01/02/top-down-operator-precedence-parsing/
# for background
# takes a tokenizer and elements
# tokenizer is an iterator that returns (type, value, pos) tuples
# elements is a mapping of types to binding strength, primary, prefix, infix
# and suffix actions
# an action is a tree node name, a tree label, and an optional match
# __call__(program) parses program into a labeled tree
from __future__ import absolute_import
from .i18n import _
from . import error
class parser(object):
def __init__(self, elements, methods=None):
self._elements = elements
self._methods = methods
self.current = None
def _advance(self):
'advance the tokenizer'
t = self.current
self.current = next(self._iter, None)
return t
def _hasnewterm(self):
'True if next token may start new term'
return any(self._elements[self.current[0]][1:3])
def _match(self, m):
'make sure the tokenizer matches an end condition'
if self.current[0] != m:
raise error.ParseError(_("unexpected token: %s") % self.current[0],
self.current[2])
self._advance()
def _parseoperand(self, bind, m=None):
'gather right-hand-side operand until an end condition or binding met'
if m and self.current[0] == m:
expr = None
else:
expr = self._parse(bind)
if m:
self._match(m)
return expr
def _parse(self, bind=0):
token, value, pos = self._advance()
# handle prefix rules on current token, take as primary if unambiguous
primary, prefix = self._elements[token][1:3]
if primary and not (prefix and self._hasnewterm()):
expr = (primary, value)
elif prefix:
expr = (prefix[0], self._parseoperand(*prefix[1:]))
else:
raise error.ParseError(_("not a prefix: %s") % token, pos)
# gather tokens until we meet a lower binding strength
while bind < self._elements[self.current[0]][0]:
token, value, pos = self._advance()
# handle infix rules, take as suffix if unambiguous
infix, suffix = self._elements[token][3:]
if suffix and not (infix and self._hasnewterm()):
expr = (suffix[0], expr)
elif infix:
expr = (infix[0], expr, self._parseoperand(*infix[1:]))
else:
raise error.ParseError(_("not an infix: %s") % token, pos)
return expr
def parse(self, tokeniter):
'generate a parse tree from tokens'
self._iter = tokeniter
self._advance()
res = self._parse()
token, value, pos = self.current
return res, pos
def eval(self, tree):
'recursively evaluate a parse tree using node methods'
if not isinstance(tree, tuple):
return tree
return self._methods[tree[0]](*[self.eval(t) for t in tree[1:]])
def __call__(self, tokeniter):
'parse tokens into a parse tree and evaluate if methods given'
t = self.parse(tokeniter)
if self._methods:
return self.eval(t)
return t
def buildargsdict(trees, funcname, keys, keyvaluenode, keynode):
"""Build dict from list containing positional and keyword arguments
Invalid keywords or too many positional arguments are rejected, but
missing arguments are just omitted.
"""
if len(trees) > len(keys):
raise error.ParseError(_("%(func)s takes at most %(nargs)d arguments")
% {'func': funcname, 'nargs': len(keys)})
args = {}
# consume positional arguments
for k, x in zip(keys, trees):
if x[0] == keyvaluenode:
break
args[k] = x
# remainder should be keyword arguments
for x in trees[len(args):]:
if x[0] != keyvaluenode or x[1][0] != keynode:
raise error.ParseError(_("%(func)s got an invalid argument")
% {'func': funcname})
k = x[1][1]
if k not in keys:
raise error.ParseError(_("%(func)s got an unexpected keyword "
"argument '%(key)s'")
% {'func': funcname, 'key': k})
if k in args:
raise error.ParseError(_("%(func)s got multiple values for keyword "
"argument '%(key)s'")
% {'func': funcname, 'key': k})
args[k] = x[2]
return args
def unescapestr(s):
try:
return s.decode("string_escape")
except ValueError as e:
# mangle Python's exception into our format
raise error.ParseError(str(e).lower())
def _prettyformat(tree, leafnodes, level, lines):
if not isinstance(tree, tuple) or tree[0] in leafnodes:
lines.append((level, str(tree)))
else:
lines.append((level, '(%s' % tree[0]))
for s in tree[1:]:
_prettyformat(s, leafnodes, level + 1, lines)
lines[-1:] = [(lines[-1][0], lines[-1][1] + ')')]
def prettyformat(tree, leafnodes):
lines = []
_prettyformat(tree, leafnodes, 0, lines)
output = '\n'.join((' ' * l + s) for l, s in lines)
return output
def simplifyinfixops(tree, targetnodes):
"""Flatten chained infix operations to reduce usage of Python stack
>>> def f(tree):
... print prettyformat(simplifyinfixops(tree, ('or',)), ('symbol',))
>>> f(('or',
... ('or',
... ('symbol', '1'),
... ('symbol', '2')),
... ('symbol', '3')))
(or
('symbol', '1')
('symbol', '2')
('symbol', '3'))
>>> f(('func',
... ('symbol', 'p1'),
... ('or',
... ('or',
... ('func',
... ('symbol', 'sort'),
... ('list',
... ('or',
... ('or',
... ('symbol', '1'),
... ('symbol', '2')),
... ('symbol', '3')),
... ('negate',
... ('symbol', 'rev')))),
... ('and',
... ('symbol', '4'),
... ('group',
... ('or',
... ('or',
... ('symbol', '5'),
... ('symbol', '6')),
... ('symbol', '7'))))),
... ('symbol', '8'))))
(func
('symbol', 'p1')
(or
(func
('symbol', 'sort')
(list
(or
('symbol', '1')
('symbol', '2')
('symbol', '3'))
(negate
('symbol', 'rev'))))
(and
('symbol', '4')
(group
(or
('symbol', '5')
('symbol', '6')
('symbol', '7'))))
('symbol', '8')))
"""
if not isinstance(tree, tuple):
return tree
op = tree[0]
if op not in targetnodes:
return (op,) + tuple(simplifyinfixops(x, targetnodes) for x in tree[1:])
# walk down left nodes taking each right node. no recursion to left nodes
# because infix operators are left-associative, i.e. left tree is deep.
# e.g. '1 + 2 + 3' -> (+ (+ 1 2) 3) -> (+ 1 2 3)
simplified = []
x = tree
while x[0] == op:
l, r = x[1:]
simplified.append(simplifyinfixops(r, targetnodes))
x = l
simplified.append(simplifyinfixops(x, targetnodes))
simplified.append(op)
return tuple(reversed(simplified))