chg: detect chg started by chg
Sometimes people may create a symbol link from hg to chg, or write a wrapper
script named hg calling chg. Without $HG and $CHGHG set, this will lead to
chg executes itself causing deadlock. The user will notice chg hangs for some
time and aborts with a timed out message, without knowing the root cause and
how to solve it.
This patch sets a dummy environment variable before executing hg to detect
this situation, and print a fatal message with some possible solutions.
CHGINTERNALMARK is set by chg client to detect the situation that chg is
started by chg. It is temporary and should be dropped to avoid possible
side effects.
# mdiff.py - diff and patch routines for mercurial
#
# Copyright 2005, 2006 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.
from __future__ import absolute_import
import re
import struct
import zlib
from .i18n import _
from . import (
base85,
bdiff,
error,
mpatch,
util,
)
def splitnewlines(text):
'''like str.splitlines, but only split on newlines.'''
lines = [l + '\n' for l in text.split('\n')]
if lines:
if lines[-1] == '\n':
lines.pop()
else:
lines[-1] = lines[-1][:-1]
return lines
class diffopts(object):
'''context is the number of context lines
text treats all files as text
showfunc enables diff -p output
git enables the git extended patch format
nodates removes dates from diff headers
nobinary ignores binary files
noprefix disables the 'a/' and 'b/' prefixes (ignored in plain mode)
ignorews ignores all whitespace changes in the diff
ignorewsamount ignores changes in the amount of whitespace
ignoreblanklines ignores changes whose lines are all blank
upgrade generates git diffs to avoid data loss
'''
defaults = {
'context': 3,
'text': False,
'showfunc': False,
'git': False,
'nodates': False,
'nobinary': False,
'noprefix': False,
'ignorews': False,
'ignorewsamount': False,
'ignoreblanklines': False,
'upgrade': False,
}
__slots__ = defaults.keys()
def __init__(self, **opts):
for k in self.__slots__:
v = opts.get(k)
if v is None:
v = self.defaults[k]
setattr(self, k, v)
try:
self.context = int(self.context)
except ValueError:
raise error.Abort(_('diff context lines count must be '
'an integer, not %r') % self.context)
def copy(self, **kwargs):
opts = dict((k, getattr(self, k)) for k in self.defaults)
opts.update(kwargs)
return diffopts(**opts)
defaultopts = diffopts()
def wsclean(opts, text, blank=True):
if opts.ignorews:
text = bdiff.fixws(text, 1)
elif opts.ignorewsamount:
text = bdiff.fixws(text, 0)
if blank and opts.ignoreblanklines:
text = re.sub('\n+', '\n', text).strip('\n')
return text
def splitblock(base1, lines1, base2, lines2, opts):
# The input lines matches except for interwoven blank lines. We
# transform it into a sequence of matching blocks and blank blocks.
lines1 = [(wsclean(opts, l) and 1 or 0) for l in lines1]
lines2 = [(wsclean(opts, l) and 1 or 0) for l in lines2]
s1, e1 = 0, len(lines1)
s2, e2 = 0, len(lines2)
while s1 < e1 or s2 < e2:
i1, i2, btype = s1, s2, '='
if (i1 >= e1 or lines1[i1] == 0
or i2 >= e2 or lines2[i2] == 0):
# Consume the block of blank lines
btype = '~'
while i1 < e1 and lines1[i1] == 0:
i1 += 1
while i2 < e2 and lines2[i2] == 0:
i2 += 1
else:
# Consume the matching lines
while i1 < e1 and lines1[i1] == 1 and lines2[i2] == 1:
i1 += 1
i2 += 1
yield [base1 + s1, base1 + i1, base2 + s2, base2 + i2], btype
s1 = i1
s2 = i2
def allblocks(text1, text2, opts=None, lines1=None, lines2=None, refine=False):
"""Return (block, type) tuples, where block is an mdiff.blocks
line entry. type is '=' for blocks matching exactly one another
(bdiff blocks), '!' for non-matching blocks and '~' for blocks
matching only after having filtered blank lines. If refine is True,
then '~' blocks are refined and are only made of blank lines.
line1 and line2 are text1 and text2 split with splitnewlines() if
they are already available.
"""
if opts is None:
opts = defaultopts
if opts.ignorews or opts.ignorewsamount:
text1 = wsclean(opts, text1, False)
text2 = wsclean(opts, text2, False)
diff = bdiff.blocks(text1, text2)
for i, s1 in enumerate(diff):
# The first match is special.
# we've either found a match starting at line 0 or a match later
# in the file. If it starts later, old and new below will both be
# empty and we'll continue to the next match.
if i > 0:
s = diff[i - 1]
else:
s = [0, 0, 0, 0]
s = [s[1], s1[0], s[3], s1[2]]
# bdiff sometimes gives huge matches past eof, this check eats them,
# and deals with the special first match case described above
if s[0] != s[1] or s[2] != s[3]:
type = '!'
if opts.ignoreblanklines:
if lines1 is None:
lines1 = splitnewlines(text1)
if lines2 is None:
lines2 = splitnewlines(text2)
old = wsclean(opts, "".join(lines1[s[0]:s[1]]))
new = wsclean(opts, "".join(lines2[s[2]:s[3]]))
if old == new:
type = '~'
yield s, type
yield s1, '='
def unidiff(a, ad, b, bd, fn1, fn2, opts=defaultopts):
def datetag(date, fn=None):
if not opts.git and not opts.nodates:
return '\t%s\n' % date
if fn and ' ' in fn:
return '\t\n'
return '\n'
if not a and not b:
return ""
if opts.noprefix:
aprefix = bprefix = ''
else:
aprefix = 'a/'
bprefix = 'b/'
epoch = util.datestr((0, 0))
fn1 = util.pconvert(fn1)
fn2 = util.pconvert(fn2)
if not opts.text and (util.binary(a) or util.binary(b)):
if a and b and len(a) == len(b) and a == b:
return ""
l = ['Binary file %s has changed\n' % fn1]
elif not a:
b = splitnewlines(b)
if a is None:
l1 = '--- /dev/null%s' % datetag(epoch)
else:
l1 = "--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1))
l2 = "+++ %s%s" % (bprefix + fn2, datetag(bd, fn2))
l3 = "@@ -0,0 +1,%d @@\n" % len(b)
l = [l1, l2, l3] + ["+" + e for e in b]
elif not b:
a = splitnewlines(a)
l1 = "--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1))
if b is None:
l2 = '+++ /dev/null%s' % datetag(epoch)
else:
l2 = "+++ %s%s%s" % (bprefix, fn2, datetag(bd, fn2))
l3 = "@@ -1,%d +0,0 @@\n" % len(a)
l = [l1, l2, l3] + ["-" + e for e in a]
else:
al = splitnewlines(a)
bl = splitnewlines(b)
l = list(_unidiff(a, b, al, bl, opts=opts))
if not l:
return ""
l.insert(0, "--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1)))
l.insert(1, "+++ %s%s%s" % (bprefix, fn2, datetag(bd, fn2)))
for ln in xrange(len(l)):
if l[ln][-1] != '\n':
l[ln] += "\n\ No newline at end of file\n"
return "".join(l)
# creates a headerless unified diff
# t1 and t2 are the text to be diffed
# l1 and l2 are the text broken up into lines
def _unidiff(t1, t2, l1, l2, opts=defaultopts):
def contextend(l, len):
ret = l + opts.context
if ret > len:
ret = len
return ret
def contextstart(l):
ret = l - opts.context
if ret < 0:
return 0
return ret
lastfunc = [0, '']
def yieldhunk(hunk):
(astart, a2, bstart, b2, delta) = hunk
aend = contextend(a2, len(l1))
alen = aend - astart
blen = b2 - bstart + aend - a2
func = ""
if opts.showfunc:
lastpos, func = lastfunc
# walk backwards from the start of the context up to the start of
# the previous hunk context until we find a line starting with an
# alphanumeric char.
for i in xrange(astart - 1, lastpos - 1, -1):
if l1[i][0].isalnum():
func = ' ' + l1[i].rstrip()[:40]
lastfunc[1] = func
break
# by recording this hunk's starting point as the next place to
# start looking for function lines, we avoid reading any line in
# the file more than once.
lastfunc[0] = astart
# zero-length hunk ranges report their start line as one less
if alen:
astart += 1
if blen:
bstart += 1
yield "@@ -%d,%d +%d,%d @@%s\n" % (astart, alen,
bstart, blen, func)
for x in delta:
yield x
for x in xrange(a2, aend):
yield ' ' + l1[x]
# bdiff.blocks gives us the matching sequences in the files. The loop
# below finds the spaces between those matching sequences and translates
# them into diff output.
#
hunk = None
ignoredlines = 0
for s, stype in allblocks(t1, t2, opts, l1, l2):
a1, a2, b1, b2 = s
if stype != '!':
if stype == '~':
# The diff context lines are based on t1 content. When
# blank lines are ignored, the new lines offsets must
# be adjusted as if equivalent blocks ('~') had the
# same sizes on both sides.
ignoredlines += (b2 - b1) - (a2 - a1)
continue
delta = []
old = l1[a1:a2]
new = l2[b1:b2]
b1 -= ignoredlines
b2 -= ignoredlines
astart = contextstart(a1)
bstart = contextstart(b1)
prev = None
if hunk:
# join with the previous hunk if it falls inside the context
if astart < hunk[1] + opts.context + 1:
prev = hunk
astart = hunk[1]
bstart = hunk[3]
else:
for x in yieldhunk(hunk):
yield x
if prev:
# we've joined the previous hunk, record the new ending points.
hunk[1] = a2
hunk[3] = b2
delta = hunk[4]
else:
# create a new hunk
hunk = [astart, a2, bstart, b2, delta]
delta[len(delta):] = [' ' + x for x in l1[astart:a1]]
delta[len(delta):] = ['-' + x for x in old]
delta[len(delta):] = ['+' + x for x in new]
if hunk:
for x in yieldhunk(hunk):
yield x
def b85diff(to, tn):
'''print base85-encoded binary diff'''
def fmtline(line):
l = len(line)
if l <= 26:
l = chr(ord('A') + l - 1)
else:
l = chr(l - 26 + ord('a') - 1)
return '%c%s\n' % (l, base85.b85encode(line, True))
def chunk(text, csize=52):
l = len(text)
i = 0
while i < l:
yield text[i:i + csize]
i += csize
if to is None:
to = ''
if tn is None:
tn = ''
if to == tn:
return ''
# TODO: deltas
ret = []
ret.append('GIT binary patch\n')
ret.append('literal %s\n' % len(tn))
for l in chunk(zlib.compress(tn)):
ret.append(fmtline(l))
ret.append('\n')
return ''.join(ret)
def patchtext(bin):
pos = 0
t = []
while pos < len(bin):
p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12])
pos += 12
t.append(bin[pos:pos + l])
pos += l
return "".join(t)
def patch(a, bin):
if len(a) == 0:
# skip over trivial delta header
return util.buffer(bin, 12)
return mpatch.patches(a, [bin])
# similar to difflib.SequenceMatcher.get_matching_blocks
def get_matching_blocks(a, b):
return [(d[0], d[2], d[1] - d[0]) for d in bdiff.blocks(a, b)]
def trivialdiffheader(length):
return struct.pack(">lll", 0, 0, length) if length else ''
def replacediffheader(oldlen, newlen):
return struct.pack(">lll", 0, oldlen, newlen)
patches = mpatch.patches
patchedsize = mpatch.patchedsize
textdiff = bdiff.bdiff