parsers: fail fast if Python has wrong minor version (issue4110)
This change causes an informative ImportError to be raised when importing
the parsers extension module if the minor version of the currently-running
Python interpreter doesn't match that of the Python used when compiling
the extension module.
This change also exposes a parsers.versionerrortext constant in the
C implementation of the module. Its presence can be used to determine
whether this behavior is present in a version of the module. The value
of the constant is the leading text of the ImportError raised and is set
to "Python minor version mismatch".
Here is an example of what the new error looks like:
Traceback (most recent call last):
File "test.py", line 1, in <module>
import mercurial.parsers
ImportError: Python minor version mismatch: The Mercurial extension
modules were compiled with Python 2.7.6, but Mercurial is currently using
Python with sys.hexversion=33883888: Python 2.5.6
(r256:88840, Nov 18 2012, 05:37:10)
[GCC 4.2.1 Compatible Apple Clang 4.1 ((tags/Apple/clang-421.11.66))]
at: /opt/local/Library/Frameworks/Python.framework/Versions/2.5/Resources/
Python.app/Contents/MacOS/Python
The reason for raising an error in this scenario is that Python's C API
is known not to be compatible from minor version to minor version, even
if sys.api_version is the same. See for example this Python bug report
about incompatibilities between 2.5 and 2.6+:
http://bugs.python.org/issue8118
These incompatibilities can cause Mercurial to break in mysterious,
unforeseen ways. For example, when Mercurial compiled with Python 2.7 was
run with 2.5, the following crash occurred when running "hg status":
http://bz.selenic.com/show_bug.cgi?id=4110
After this crash was fixed, running with Python 2.5 no longer crashes, but
the following puzzling behavior still occurs:
$ hg status
...
File ".../mercurial/changelog.py", line 123, in __init__
revlog.revlog.__init__(self, opener, "00changelog.i")
File ".../mercurial/revlog.py", line 251, in __init__
d = self._io.parseindex(i, self._inline)
File ".../mercurial/revlog.py", line 158, in parseindex
index, cache = parsers.parse_index2(data, inline)
TypeError: data is not a string
which can be reproduced more simply with:
import mercurial.parsers as parsers
parsers.parse_index2("", True)
Both the crash and the TypeError occurred because the Python C API's
PyString_Check() returns the wrong value when the C header files from
Python 2.7 are run with Python 2.5. This is an example of an
incompatibility of the sort mentioned in the Python bug report above.
Failing fast with an informative error message results in a better user
experience in cases like the above. The information in the ImportError
also simplifies troubleshooting for those on Mercurial mailing lists, the
bug tracker, etc.
This patch only adds the version check to parsers.c, which is sufficient
to affect command-line commands like "hg status" and "hg summary".
An idea for a future improvement is to move the version-checking C code
to a more central location, and have it run when importing all
Mercurial extension modules and not just parsers.c.
# archival.py - revision archival for mercurial
#
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.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 i18n import _
from node import hex
import match as matchmod
import cmdutil
import scmutil, util, encoding
import cStringIO, os, tarfile, time, zipfile
import zlib, gzip
import struct
import error
# from unzip source code:
_UNX_IFREG = 0x8000
_UNX_IFLNK = 0xa000
def tidyprefix(dest, kind, prefix):
'''choose prefix to use for names in archive. make sure prefix is
safe for consumers.'''
if prefix:
prefix = util.normpath(prefix)
else:
if not isinstance(dest, str):
raise ValueError('dest must be string if no prefix')
prefix = os.path.basename(dest)
lower = prefix.lower()
for sfx in exts.get(kind, []):
if lower.endswith(sfx):
prefix = prefix[:-len(sfx)]
break
lpfx = os.path.normpath(util.localpath(prefix))
prefix = util.pconvert(lpfx)
if not prefix.endswith('/'):
prefix += '/'
if prefix.startswith('../') or os.path.isabs(lpfx) or '/../' in prefix:
raise util.Abort(_('archive prefix contains illegal components'))
return prefix
exts = {
'tar': ['.tar'],
'tbz2': ['.tbz2', '.tar.bz2'],
'tgz': ['.tgz', '.tar.gz'],
'zip': ['.zip'],
}
def guesskind(dest):
for kind, extensions in exts.iteritems():
if util.any(dest.endswith(ext) for ext in extensions):
return kind
return None
class tarit(object):
'''write archive to tar file or stream. can write uncompressed,
or compress with gzip or bzip2.'''
class GzipFileWithTime(gzip.GzipFile):
def __init__(self, *args, **kw):
timestamp = None
if 'timestamp' in kw:
timestamp = kw.pop('timestamp')
if timestamp is None:
self.timestamp = time.time()
else:
self.timestamp = timestamp
gzip.GzipFile.__init__(self, *args, **kw)
def _write_gzip_header(self):
self.fileobj.write('\037\213') # magic header
self.fileobj.write('\010') # compression method
# Python 2.6 introduced self.name and deprecated self.filename
try:
fname = self.name
except AttributeError:
fname = self.filename
if fname and fname.endswith('.gz'):
fname = fname[:-3]
flags = 0
if fname:
flags = gzip.FNAME
self.fileobj.write(chr(flags))
gzip.write32u(self.fileobj, long(self.timestamp))
self.fileobj.write('\002')
self.fileobj.write('\377')
if fname:
self.fileobj.write(fname + '\000')
def __init__(self, dest, mtime, kind=''):
self.mtime = mtime
self.fileobj = None
def taropen(name, mode, fileobj=None):
if kind == 'gz':
mode = mode[0]
if not fileobj:
fileobj = open(name, mode + 'b')
gzfileobj = self.GzipFileWithTime(name, mode + 'b',
zlib.Z_BEST_COMPRESSION,
fileobj, timestamp=mtime)
self.fileobj = gzfileobj
return tarfile.TarFile.taropen(name, mode, gzfileobj)
else:
return tarfile.open(name, mode + kind, fileobj)
if isinstance(dest, str):
self.z = taropen(dest, mode='w:')
else:
# Python 2.5-2.5.1 have a regression that requires a name arg
self.z = taropen(name='', mode='w|', fileobj=dest)
def addfile(self, name, mode, islink, data):
i = tarfile.TarInfo(name)
i.mtime = self.mtime
i.size = len(data)
if islink:
i.type = tarfile.SYMTYPE
i.mode = 0777
i.linkname = data
data = None
i.size = 0
else:
i.mode = mode
data = cStringIO.StringIO(data)
self.z.addfile(i, data)
def done(self):
self.z.close()
if self.fileobj:
self.fileobj.close()
class tellable(object):
'''provide tell method for zipfile.ZipFile when writing to http
response file object.'''
def __init__(self, fp):
self.fp = fp
self.offset = 0
def __getattr__(self, key):
return getattr(self.fp, key)
def write(self, s):
self.fp.write(s)
self.offset += len(s)
def tell(self):
return self.offset
class zipit(object):
'''write archive to zip file or stream. can write uncompressed,
or compressed with deflate.'''
def __init__(self, dest, mtime, compress=True):
if not isinstance(dest, str):
try:
dest.tell()
except (AttributeError, IOError):
dest = tellable(dest)
self.z = zipfile.ZipFile(dest, 'w',
compress and zipfile.ZIP_DEFLATED or
zipfile.ZIP_STORED)
# Python's zipfile module emits deprecation warnings if we try
# to store files with a date before 1980.
epoch = 315532800 # calendar.timegm((1980, 1, 1, 0, 0, 0, 1, 1, 0))
if mtime < epoch:
mtime = epoch
self.mtime = mtime
self.date_time = time.gmtime(mtime)[:6]
def addfile(self, name, mode, islink, data):
i = zipfile.ZipInfo(name, self.date_time)
i.compress_type = self.z.compression
# unzip will not honor unix file modes unless file creator is
# set to unix (id 3).
i.create_system = 3
ftype = _UNX_IFREG
if islink:
mode = 0777
ftype = _UNX_IFLNK
i.external_attr = (mode | ftype) << 16L
# add "extended-timestamp" extra block, because zip archives
# without this will be extracted with unexpected timestamp,
# if TZ is not configured as GMT
i.extra += struct.pack('<hhBl',
0x5455, # block type: "extended-timestamp"
1 + 4, # size of this block
1, # "modification time is present"
int(self.mtime)) # last modification (UTC)
self.z.writestr(i, data)
def done(self):
self.z.close()
class fileit(object):
'''write archive as files in directory.'''
def __init__(self, name, mtime):
self.basedir = name
self.opener = scmutil.opener(self.basedir)
def addfile(self, name, mode, islink, data):
if islink:
self.opener.symlink(data, name)
return
f = self.opener(name, "w", atomictemp=True)
f.write(data)
f.close()
destfile = os.path.join(self.basedir, name)
os.chmod(destfile, mode)
def done(self):
pass
archivers = {
'files': fileit,
'tar': tarit,
'tbz2': lambda name, mtime: tarit(name, mtime, 'bz2'),
'tgz': lambda name, mtime: tarit(name, mtime, 'gz'),
'uzip': lambda name, mtime: zipit(name, mtime, False),
'zip': zipit,
}
def archive(repo, dest, node, kind, decode=True, matchfn=None,
prefix=None, mtime=None, subrepos=False):
'''create archive of repo as it was at node.
dest can be name of directory, name of archive file, or file
object to write archive to.
kind is type of archive to create.
decode tells whether to put files through decode filters from
hgrc.
matchfn is function to filter names of files to write to archive.
prefix is name of path to put before every archive member.'''
if kind == 'files':
if prefix:
raise util.Abort(_('cannot give prefix when archiving to files'))
else:
prefix = tidyprefix(dest, kind, prefix)
def write(name, mode, islink, getdata):
data = getdata()
if decode:
data = repo.wwritedata(name, data)
archiver.addfile(prefix + name, mode, islink, data)
if kind not in archivers:
raise util.Abort(_("unknown archive type '%s'") % kind)
ctx = repo[node]
archiver = archivers[kind](dest, mtime or ctx.date()[0])
if repo.ui.configbool("ui", "archivemeta", True):
def metadata():
base = 'repo: %s\nnode: %s\nbranch: %s\n' % (
repo[0].hex(), hex(node), encoding.fromlocal(ctx.branch()))
tags = ''.join('tag: %s\n' % t for t in ctx.tags()
if repo.tagtype(t) == 'global')
if not tags:
repo.ui.pushbuffer()
opts = {'template': '{latesttag}\n{latesttagdistance}',
'style': '', 'patch': None, 'git': None}
cmdutil.show_changeset(repo.ui, repo, opts).show(ctx)
ltags, dist = repo.ui.popbuffer().split('\n')
tags = ''.join('latesttag: %s\n' % t for t in ltags.split(':'))
tags += 'latesttagdistance: %s\n' % dist
return base + tags
name = '.hg_archival.txt'
if not matchfn or matchfn(name):
write(name, 0644, False, metadata)
if matchfn:
files = [f for f in ctx.manifest().keys() if matchfn(f)]
else:
files = ctx.manifest().keys()
total = len(files)
if total:
files.sort()
repo.ui.progress(_('archiving'), 0, unit=_('files'), total=total)
for i, f in enumerate(files):
ff = ctx.flags(f)
write(f, 'x' in ff and 0755 or 0644, 'l' in ff, ctx[f].data)
repo.ui.progress(_('archiving'), i + 1, item=f,
unit=_('files'), total=total)
repo.ui.progress(_('archiving'), None)
if subrepos:
for subpath in sorted(ctx.substate):
sub = ctx.sub(subpath)
submatch = matchmod.narrowmatcher(subpath, matchfn)
total += sub.archive(repo.ui, archiver, prefix, submatch)
if total == 0:
raise error.Abort(_('no files match the archive pattern'))
archiver.done()
return total