icasefs: make case-folding collision detection as deletion aware (issue3648)
Before this patch, case-folding collision is checked simply between
manifests of each merged revisions.
So, files may be considered as colliding each other, even though one
of them is already deleted on one of merged branches: in such case,
merge causes deleting it, so case-folding collision doesn't occur.
This patch checks whether both of files colliding each other still
remain after merge or not, and ignores collision if at least one of
them is deleted by merge.
In the case that one of colliding files is deleted on one of merged
branches and changed on another, file is considered to still remain
after merge, even though it may be deleted by merge, if "deleting" of
it is chosen in "manifestmerge()".
This avoids fail to merge by case-folding collisions after choices
from "changing" and "deleting" of files.
This patch adds only tests for "removed remotely" code paths in
"_remains()", because other ones are tested by existing tests in
"test-casecollision-merge.t".
# 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 pairs
# elements is a mapping of types to binding strength, prefix and infix actions
# an action is a tree node name, a tree label, and an optional match
# __call__(program) parses program into a labeled tree
import error
from i18n import _
class parser(object):
def __init__(self, tokenizer, elements, methods=None):
self._tokenizer = tokenizer
self._elements = elements
self._methods = methods
self.current = None
def _advance(self):
'advance the tokenizer'
t = self.current
try:
self.current = self._iter.next()
except StopIteration:
pass
return t
def _match(self, m, pos):
'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 _parse(self, bind=0):
token, value, pos = self._advance()
# handle prefix rules on current token
prefix = self._elements[token][1]
if not prefix:
raise error.ParseError(_("not a prefix: %s") % token, pos)
if len(prefix) == 1:
expr = (prefix[0], value)
else:
if len(prefix) > 2 and prefix[2] == self.current[0]:
self._match(prefix[2], pos)
expr = (prefix[0], None)
else:
expr = (prefix[0], self._parse(prefix[1]))
if len(prefix) > 2:
self._match(prefix[2], pos)
# gather tokens until we meet a lower binding strength
while bind < self._elements[self.current[0]][0]:
token, value, pos = self._advance()
e = self._elements[token]
# check for suffix - next token isn't a valid prefix
if len(e) == 4 and not self._elements[self.current[0]][1]:
suffix = e[3]
expr = (suffix[0], expr)
else:
# handle infix rules
if len(e) < 3 or not e[2]:
raise error.ParseError(_("not an infix: %s") % token, pos)
infix = e[2]
if len(infix) == 3 and infix[2] == self.current[0]:
self._match(infix[2], pos)
expr = (infix[0], expr, (None))
else:
expr = (infix[0], expr, self._parse(infix[1]))
if len(infix) == 3:
self._match(infix[2], pos)
return expr
def parse(self, message):
'generate a parse tree from a message'
self._iter = self._tokenizer(message)
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, message):
'parse a message into a parse tree and evaluate if methods given'
t = self.parse(message)
if self._methods:
return self.eval(t)
return t