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parsers: fail fast if Python has wrong minor version (issue4110)...
parsers: fail fast if Python has wrong minor version (issue4110) This change causes an informative ImportError to be raised when importing the extension module parsers if the minor version of the currently-running Python interpreter doesn't match that of the Python that was used when compiling the extension module. 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 will result in a better user experience in cases like the above. The information in the ImportError will also simplify 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.

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simplemerge
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Alexis S. L. Carvalho
actually port simplemerge to hg...
r4363 #!/usr/bin/env python
Alexis S. L. Carvalho
Import 3-way merge code from bzr...
r4362
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 from mercurial import demandimport
demandimport.enable()
Alexis S. L. Carvalho
Import 3-way merge code from bzr...
r4362
Simon Heimberg
cleanup: drop unused variables and an unused import
r19378 import sys
Alexis S. L. Carvalho
actually port simplemerge to hg...
r4363 from mercurial.i18n import _
Steve Borho
simplemerge: use ui.warn() for warnings
r8269 from mercurial import simplemerge, fancyopts, util, ui
Alexis S. L. Carvalho
Import 3-way merge code from bzr...
r4362
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 options = [('L', 'label', [], _('labels to use on conflict markers')),
('a', 'text', None, _('treat all files as text')),
('p', 'print', None,
_('print results instead of overwriting LOCAL')),
('', 'no-minimal', None,
_('do not try to minimize conflict regions')),
('h', 'help', None, _('display help and exit')),
('q', 'quiet', None, _('suppress output'))]
usage = _('''simplemerge [OPTS] LOCAL BASE OTHER
Simple three-way file merge utility with a minimal feature set.
Thomas Arendsen Hein
Remove trailing spaces
r5081
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 Apply to LOCAL the changes necessary to go from BASE to OTHER.
Thomas Arendsen Hein
Remove trailing spaces
r5081
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 By default, LOCAL is overwritten with the results of this operation.
''')
Matt Mackall
merge: move the bulk of simplemerge into core...
r6002 class ParseError(Exception):
"""Exception raised on errors in parsing the command line."""
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 def showhelp():
sys.stdout.write(usage)
sys.stdout.write('\noptions:\n')
Alexis S. L. Carvalho
Import 3-way merge code from bzr...
r4362
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 out_opts = []
for shortopt, longopt, default, desc in options:
out_opts.append(('%2s%s' % (shortopt and '-%s' % shortopt,
longopt and ' --%s' % longopt),
'%s' % desc))
opts_len = max([len(opt[0]) for opt in out_opts])
for first, second in out_opts:
sys.stdout.write(' %-*s %s\n' % (opts_len, first, second))
Matt Mackall
merge: move the bulk of simplemerge into core...
r6002 try:
Patrick Mezard
tests: Windows compatibility fixes...
r7080 for fp in (sys.stdin, sys.stdout, sys.stderr):
Adrian Buehlmann
rename util.set_binary to setbinary
r14233 util.setbinary(fp)
Mads Kiilerich
tests: run check-code on Python files without .py extension
r19022
Matt Mackall
merge: move the bulk of simplemerge into core...
r6002 opts = {}
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 try:
Matt Mackall
merge: move the bulk of simplemerge into core...
r6002 args = fancyopts.fancyopts(sys.argv[1:], options, opts)
except fancyopts.getopt.GetoptError, e:
raise ParseError(e)
if opts['help']:
Alexis S. L. Carvalho
polish the simplemerge command; add a test
r4364 showhelp()
Matt Mackall
merge: move the bulk of simplemerge into core...
r6002 sys.exit(0)
if len(args) != 3:
raise ParseError(_('wrong number of arguments'))
Steve Borho
simplemerge: use ui.warn() for warnings
r8269 sys.exit(simplemerge.simplemerge(ui.ui(), *args, **opts))
Matt Mackall
merge: move the bulk of simplemerge into core...
r6002 except ParseError, e:
sys.stdout.write("%s: %s\n" % (sys.argv[0], e))
showhelp()
sys.exit(1)
except util.Abort, e:
sys.stderr.write("abort: %s\n" % e)
sys.exit(255)
except KeyboardInterrupt:
sys.exit(255)