Mercurial > hg
view hgext/win32text.py @ 20742:3681de20b0a7
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.
author | Chris Jerdonek <chris.jerdonek@gmail.com> |
---|---|
date | Wed, 04 Dec 2013 20:38:27 -0800 |
parents | 23146e4d9cee |
children | 80c5b2666a96 |
line wrap: on
line source
# win32text.py - LF <-> CRLF/CR translation utilities for Windows/Mac users # # Copyright 2005, 2007-2009 Matt Mackall <mpm@selenic.com> 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. '''perform automatic newline conversion (DEPRECATED) Deprecation: The win32text extension requires each user to configure the extension again and again for each clone since the configuration is not copied when cloning. We have therefore made the ``eol`` as an alternative. The ``eol`` uses a version controlled file for its configuration and each clone will therefore use the right settings from the start. To perform automatic newline conversion, use:: [extensions] win32text = [encode] ** = cleverencode: # or ** = macencode: [decode] ** = cleverdecode: # or ** = macdecode: If not doing conversion, to make sure you do not commit CRLF/CR by accident:: [hooks] pretxncommit.crlf = python:hgext.win32text.forbidcrlf # or pretxncommit.cr = python:hgext.win32text.forbidcr To do the same check on a server to prevent CRLF/CR from being pushed or pulled:: [hooks] pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf # or pretxnchangegroup.cr = python:hgext.win32text.forbidcr ''' from mercurial.i18n import _ from mercurial.node import short from mercurial import util import re testedwith = 'internal' # regexp for single LF without CR preceding. re_single_lf = re.compile('(^|[^\r])\n', re.MULTILINE) newlinestr = {'\r\n': 'CRLF', '\r': 'CR'} filterstr = {'\r\n': 'clever', '\r': 'mac'} def checknewline(s, newline, ui=None, repo=None, filename=None): # warn if already has 'newline' in repository. # it might cause unexpected eol conversion. # see issue 302: # http://mercurial.selenic.com/bts/issue302 if newline in s and ui and filename and repo: ui.warn(_('WARNING: %s already has %s line endings\n' 'and does not need EOL conversion by the win32text plugin.\n' 'Before your next commit, please reconsider your ' 'encode/decode settings in \nMercurial.ini or %s.\n') % (filename, newlinestr[newline], repo.join('hgrc'))) def dumbdecode(s, cmd, **kwargs): checknewline(s, '\r\n', **kwargs) # replace single LF to CRLF return re_single_lf.sub('\\1\r\n', s) def dumbencode(s, cmd): return s.replace('\r\n', '\n') def macdumbdecode(s, cmd, **kwargs): checknewline(s, '\r', **kwargs) return s.replace('\n', '\r') def macdumbencode(s, cmd): return s.replace('\r', '\n') def cleverdecode(s, cmd, **kwargs): if not util.binary(s): return dumbdecode(s, cmd, **kwargs) return s def cleverencode(s, cmd): if not util.binary(s): return dumbencode(s, cmd) return s def macdecode(s, cmd, **kwargs): if not util.binary(s): return macdumbdecode(s, cmd, **kwargs) return s def macencode(s, cmd): if not util.binary(s): return macdumbencode(s, cmd) return s _filters = { 'dumbdecode:': dumbdecode, 'dumbencode:': dumbencode, 'cleverdecode:': cleverdecode, 'cleverencode:': cleverencode, 'macdumbdecode:': macdumbdecode, 'macdumbencode:': macdumbencode, 'macdecode:': macdecode, 'macencode:': macencode, } def forbidnewline(ui, repo, hooktype, node, newline, **kwargs): halt = False seen = set() # we try to walk changesets in reverse order from newest to # oldest, so that if we see a file multiple times, we take the # newest version as canonical. this prevents us from blocking a # changegroup that contains an unacceptable commit followed later # by a commit that fixes the problem. tip = repo['tip'] for rev in xrange(len(repo) - 1, repo[node].rev() - 1, -1): c = repo[rev] for f in c.files(): if f in seen or f not in tip or f not in c: continue seen.add(f) data = c[f].data() if not util.binary(data) and newline in data: if not halt: ui.warn(_('attempt to commit or push text file(s) ' 'using %s line endings\n') % newlinestr[newline]) ui.warn(_('in %s: %s\n') % (short(c.node()), f)) halt = True if halt and hooktype == 'pretxnchangegroup': crlf = newlinestr[newline].lower() filter = filterstr[newline] ui.warn(_('\nTo prevent this mistake in your local repository,\n' 'add to Mercurial.ini or .hg/hgrc:\n' '\n' '[hooks]\n' 'pretxncommit.%s = python:hgext.win32text.forbid%s\n' '\n' 'and also consider adding:\n' '\n' '[extensions]\n' 'win32text =\n' '[encode]\n' '** = %sencode:\n' '[decode]\n' '** = %sdecode:\n') % (crlf, crlf, filter, filter)) return halt def forbidcrlf(ui, repo, hooktype, node, **kwargs): return forbidnewline(ui, repo, hooktype, node, '\r\n', **kwargs) def forbidcr(ui, repo, hooktype, node, **kwargs): return forbidnewline(ui, repo, hooktype, node, '\r', **kwargs) def reposetup(ui, repo): if not repo.local(): return for name, fn in _filters.iteritems(): repo.adddatafilter(name, fn) def extsetup(ui): if ui.configbool('win32text', 'warn', True): ui.warn(_("win32text is deprecated: " "http://mercurial.selenic.com/wiki/Win32TextExtension\n"))