view tests/test-encoding.t @ 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.

Test character encoding

  $ hg init t
  $ cd t

we need a repo with some legacy latin-1 changesets

  $ hg unbundle "$TESTDIR/bundles/legacy-encoding.hg"
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg co
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ python << EOF
  > f = file('latin-1', 'w'); f.write("latin-1 e' encoded: \xe9"); f.close()
  > f = file('utf-8', 'w'); f.write("utf-8 e' encoded: \xc3\xa9"); f.close()
  > f = file('latin-1-tag', 'w'); f.write("\xe9"); f.close()
  > EOF

should fail with encoding error

  $ echo "plain old ascii" > a
  $ hg st
  M a
  ? latin-1
  ? latin-1-tag
  ? utf-8
  $ HGENCODING=ascii hg ci -l latin-1
  transaction abort!
  rollback completed
  abort: decoding near ' encoded: \xe9': 'ascii' codec can't decode byte 0xe9 in position 20: ordinal not in range(128)! (esc)
  [255]

these should work

  $ echo "latin-1" > a
  $ HGENCODING=latin-1 hg ci -l latin-1
  $ echo "utf-8" > a
  $ HGENCODING=utf-8 hg ci -l utf-8
  $ HGENCODING=latin-1 hg tag `cat latin-1-tag`
  $ HGENCODING=latin-1 hg branch `cat latin-1-tag`
  marked working directory as branch \xe9 (esc)
  (branches are permanent and global, did you want a bookmark?)
  $ HGENCODING=latin-1 hg ci -m 'latin1 branch'
  $ hg -q rollback
  $ HGENCODING=latin-1 hg branch
  \xe9 (esc)
  $ HGENCODING=latin-1 hg ci -m 'latin1 branch'
  $ rm .hg/branch

hg log (ascii)

  $ hg --encoding ascii log
  changeset:   5:a52c0692f24a
  branch:      ?
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin1 branch
  
  changeset:   4:94db611b4196
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag ? for changeset ca661e7520de
  
  changeset:   3:ca661e7520de
  tag:         ?
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     utf-8 e' encoded: ?
  
  changeset:   2:650c6f3d55dd
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin-1 e' encoded: ?
  
  changeset:   1:0e5b7e3f9c4a
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     koi8-r: ????? = u'\u0440\u0442\u0443\u0442\u044c'
  
  changeset:   0:1e78a93102a3
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     latin-1 e': ? = u'\xe9'
  

hg log (latin-1)

  $ hg --encoding latin-1 log
  changeset:   5:a52c0692f24a
  branch:      \xe9 (esc)
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin1 branch
  
  changeset:   4:94db611b4196
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag \xe9 for changeset ca661e7520de (esc)
  
  changeset:   3:ca661e7520de
  tag:         \xe9 (esc)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     utf-8 e' encoded: \xe9 (esc)
  
  changeset:   2:650c6f3d55dd
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin-1 e' encoded: \xe9 (esc)
  
  changeset:   1:0e5b7e3f9c4a
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     koi8-r: \xd2\xd4\xd5\xd4\xd8 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
  
  changeset:   0:1e78a93102a3
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     latin-1 e': \xe9 = u'\\xe9' (esc)
  

hg log (utf-8)

  $ hg --encoding utf-8 log
  changeset:   5:a52c0692f24a
  branch:      \xc3\xa9 (esc)
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin1 branch
  
  changeset:   4:94db611b4196
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag \xc3\xa9 for changeset ca661e7520de (esc)
  
  changeset:   3:ca661e7520de
  tag:         \xc3\xa9 (esc)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     utf-8 e' encoded: \xc3\xa9 (esc)
  
  changeset:   2:650c6f3d55dd
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin-1 e' encoded: \xc3\xa9 (esc)
  
  changeset:   1:0e5b7e3f9c4a
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     koi8-r: \xc3\x92\xc3\x94\xc3\x95\xc3\x94\xc3\x98 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
  
  changeset:   0:1e78a93102a3
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     latin-1 e': \xc3\xa9 = u'\\xe9' (esc)
  

hg tags (ascii)

  $ HGENCODING=ascii hg tags
  tip                                5:a52c0692f24a
  ?                                  3:ca661e7520de

hg tags (latin-1)

  $ HGENCODING=latin-1 hg tags
  tip                                5:a52c0692f24a
  \xe9                                  3:ca661e7520de (esc)

hg tags (utf-8)

  $ HGENCODING=utf-8 hg tags
  tip                                5:a52c0692f24a
  \xc3\xa9                                  3:ca661e7520de (esc)

hg branches (ascii)

  $ HGENCODING=ascii hg branches
  ?                              5:a52c0692f24a
  default                        4:94db611b4196 (inactive)

hg branches (latin-1)

  $ HGENCODING=latin-1 hg branches
  \xe9                              5:a52c0692f24a (esc)
  default                        4:94db611b4196 (inactive)

hg branches (utf-8)

  $ HGENCODING=utf-8 hg branches
  \xc3\xa9                              5:a52c0692f24a (esc)
  default                        4:94db611b4196 (inactive)
  $ echo '[ui]' >> .hg/hgrc
  $ echo 'fallbackencoding = koi8-r' >> .hg/hgrc

hg log (utf-8)

  $ HGENCODING=utf-8 hg log
  changeset:   5:a52c0692f24a
  branch:      \xc3\xa9 (esc)
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin1 branch
  
  changeset:   4:94db611b4196
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag \xc3\xa9 for changeset ca661e7520de (esc)
  
  changeset:   3:ca661e7520de
  tag:         \xc3\xa9 (esc)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     utf-8 e' encoded: \xc3\xa9 (esc)
  
  changeset:   2:650c6f3d55dd
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     latin-1 e' encoded: \xc3\xa9 (esc)
  
  changeset:   1:0e5b7e3f9c4a
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     koi8-r: \xd1\x80\xd1\x82\xd1\x83\xd1\x82\xd1\x8c = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
  
  changeset:   0:1e78a93102a3
  user:        test
  date:        Mon Jan 12 13:46:40 1970 +0000
  summary:     latin-1 e': \xd0\x98 = u'\\xe9' (esc)
  

hg log (dolphin)

  $ HGENCODING=dolphin hg log
  abort: unknown encoding: dolphin
  (please check your locale settings)
  [255]
  $ HGENCODING=ascii hg branch `cat latin-1-tag`
  abort: decoding near '\xe9': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)! (esc)
  [255]
  $ cp latin-1-tag .hg/branch
  $ HGENCODING=latin-1 hg ci -m 'auto-promote legacy name'

Test roundtrip encoding of lookup tables when not using UTF-8 (issue2763)

  $ HGENCODING=latin-1 hg up `cat latin-1-tag`
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cd ..