view tests/test-url-rev.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 basic functionality of url#rev syntax

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -qAm 'add a'
  $ hg branch foo
  marked working directory as branch foo
  (branches are permanent and global, did you want a bookmark?)
  $ echo >> a
  $ hg ci -m 'change a'
  $ cd ..

  $ hg clone 'repo#foo' clone
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  updating to branch foo
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg --cwd clone heads
  changeset:   1:cd2a86ecc814
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change a
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg --cwd clone parents
  changeset:   1:cd2a86ecc814
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change a
  
  $ cat clone/.hg/hgrc
  [paths]
  default = $TESTTMP/repo#foo (glob)

Changing original repo:

  $ cd repo

  $ echo >> a
  $ hg ci -m 'new head of branch foo'

  $ hg up -qC default
  $ echo bar > bar
  $ hg ci -qAm 'add bar'

  $ hg log
  changeset:   3:4cd725637392
  tag:         tip
  parent:      0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  changeset:   2:faba9097cad4
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  changeset:   1:cd2a86ecc814
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change a
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg -q outgoing '../clone'
  2:faba9097cad4
  3:4cd725637392
  $ hg summary --remote --config paths.default='../clone'
  parent: 3:4cd725637392 tip
   add bar
  branch: default
  commit: (clean)
  update: (current)
  remote: 2 outgoing
  $ hg -q outgoing '../clone#foo'
  2:faba9097cad4
  $ hg summary --remote --config paths.default='../clone#foo'
  parent: 3:4cd725637392 tip
   add bar
  branch: default
  commit: (clean)
  update: (current)
  remote: 1 outgoing

  $ hg -q --cwd ../clone incoming '../repo#foo'
  2:faba9097cad4
  $ hg --cwd ../clone summary --remote --config paths.default='../repo#foo'
  parent: 1:cd2a86ecc814 tip
   change a
  branch: foo
  commit: (clean)
  update: (current)
  remote: 1 or more incoming

  $ hg -q push '../clone#foo'

  $ hg --cwd ../clone heads
  changeset:   2:faba9097cad4
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg -q --cwd ../clone incoming '../repo#foo'
  [1]
  $ hg --cwd ../clone summary --remote --config paths.default='../repo#foo'
  parent: 1:cd2a86ecc814 
   change a
  branch: foo
  commit: (clean)
  update: 1 new changesets (update)
  remote: (synced)

  $ cd ..

  $ cd clone
  $ hg rollback
  repository tip rolled back to revision 1 (undo push)

  $ hg -q incoming
  2:faba9097cad4

  $ hg -q pull

  $ hg heads
  changeset:   2:faba9097cad4
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
Pull should not have updated:

  $ hg parents -q
  1:cd2a86ecc814

Going back to the default branch:

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg parents
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
No new revs, no update:

  $ hg pull -qu

  $ hg parents -q
  0:1f0dee641bb7

  $ hg rollback
  repository tip rolled back to revision 1 (undo pull)

  $ hg parents -q
  0:1f0dee641bb7

Pull -u takes us back to branch foo:

  $ hg pull -qu

  $ hg parents
  changeset:   2:faba9097cad4
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  $ hg rollback
  repository tip rolled back to revision 1 (undo pull)
  working directory now based on revision 0

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg parents -q
  0:1f0dee641bb7

  $ hg heads -q
  1:cd2a86ecc814
  0:1f0dee641bb7

  $ hg pull -qur default default

  $ hg parents
  changeset:   3:4cd725637392
  tag:         tip
  parent:      0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  $ hg heads
  changeset:   3:4cd725637392
  tag:         tip
  parent:      0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  changeset:   2:faba9097cad4
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
Test handling of invalid urls

  $ hg id http://foo/?bar
  abort: unsupported URL component: "bar"
  [255]

  $ cd ..

Test handling common incoming revisions between "default" and
"default-push"

  $ hg -R clone rollback
  repository tip rolled back to revision 1 (undo pull)
  working directory now based on revision 0

  $ cd repo

  $ hg update -q -C default
  $ echo modified >> bar
  $ hg commit -m "new head to push current default head"
  $ hg -q push -r ".^1" '../clone'

  $ hg -q outgoing '../clone'
  2:faba9097cad4
  4:d515801a8f3d

  $ hg summary --remote --config paths.default='../clone#default' --config paths.default-push='../clone#foo'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  remote: 1 outgoing

  $ hg summary --remote --config paths.default='../clone#foo' --config paths.default-push='../clone'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  remote: 2 outgoing

  $ hg summary --remote --config paths.default='../clone' --config paths.default-push='../clone#foo'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  remote: 1 outgoing

  $ hg clone -q -r 0 . ../another
  $ hg -q outgoing '../another#default'
  3:4cd725637392
  4:d515801a8f3d

  $ hg summary --remote --config paths.default='../another#default' --config paths.default-push='../clone#default'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  remote: 1 outgoing

  $ cd ..