view tests/test-strip.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.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "strip=" >> $HGRCPATH

  $ restore() {
  >     hg unbundle -q .hg/strip-backup/*
  >     rm .hg/strip-backup/*
  > }
  $ teststrip() {
  >     hg up -C $1
  >     echo % before update $1, strip $2
  >     hg parents
  >     hg --traceback strip $2
  >     echo % after update $1, strip $2
  >     hg parents
  >     restore
  > }

  $ hg init test
  $ cd test

  $ echo foo > bar
  $ hg ci -Ama
  adding bar

  $ echo more >> bar
  $ hg ci -Amb

  $ echo blah >> bar
  $ hg ci -Amc

  $ hg up 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo blah >> bar
  $ hg ci -Amd
  created new head

  $ echo final >> bar
  $ hg ci -Ame

  $ hg log
  changeset:   4:443431ffac4f
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  changeset:   3:65bd5f99a4a3
  parent:      1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     d
  
  changeset:   2:264128213d29
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  changeset:   0:9ab35a2d17cb
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  

  $ teststrip 4 4
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % before update 4, strip 4
  changeset:   4:443431ffac4f
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  % after update 4, strip 4
  changeset:   3:65bd5f99a4a3
  tag:         tip
  parent:      1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     d
  
  $ teststrip 4 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % before update 4, strip 3
  changeset:   4:443431ffac4f
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  % after update 4, strip 3
  changeset:   1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  $ teststrip 1 4
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % before update 1, strip 4
  changeset:   1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  % after update 1, strip 4
  changeset:   1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  $ teststrip 4 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % before update 4, strip 2
  changeset:   4:443431ffac4f
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  % after update 4, strip 2
  changeset:   3:443431ffac4f
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  $ teststrip 4 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % before update 4, strip 1
  changeset:   4:264128213d29
  tag:         tip
  parent:      1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  % after update 4, strip 1
  changeset:   0:9ab35a2d17cb
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  $ teststrip null 4
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  % before update null, strip 4
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  % after update null, strip 4

  $ hg log
  changeset:   4:264128213d29
  tag:         tip
  parent:      1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   3:443431ffac4f
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  changeset:   2:65bd5f99a4a3
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     d
  
  changeset:   1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  changeset:   0:9ab35a2d17cb
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  

  $ hg up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 4
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

before strip of merge parent

  $ hg parents
  changeset:   2:65bd5f99a4a3
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     d
  
  changeset:   4:264128213d29
  tag:         tip
  parent:      1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  $ hg strip 4
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)

after strip of merge parent

  $ hg parents
  changeset:   1:ef3a871183d7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  $ restore

  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G
  @  changeset:   4:264128213d29
  |  tag:         tip
  |  parent:      1:ef3a871183d7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  | o  changeset:   3:443431ffac4f
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     e
  | |
  | o  changeset:   2:65bd5f99a4a3
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     d
  |
  o  changeset:   1:ef3a871183d7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:9ab35a2d17cb
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

2 is parent of 3, only one strip should happen

  $ hg strip "roots(2)" 3
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  $ hg log -G
  @  changeset:   2:264128213d29
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:ef3a871183d7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:9ab35a2d17cb
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  
  $ restore
  $ hg log -G
  o  changeset:   4:443431ffac4f
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     e
  |
  o  changeset:   3:65bd5f99a4a3
  |  parent:      1:ef3a871183d7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  | @  changeset:   2:264128213d29
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     c
  |
  o  changeset:   1:ef3a871183d7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:9ab35a2d17cb
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

2 different branches: 2 strips

  $ hg strip 2 4
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  $ hg log -G
  o  changeset:   2:65bd5f99a4a3
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  @  changeset:   1:ef3a871183d7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:9ab35a2d17cb
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  
  $ restore

2 different branches and a common ancestor: 1 strip

  $ hg strip 1 "2|4"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  $ restore

stripping an empty revset

  $ hg strip "1 and not 1"
  abort: empty revision set
  [255]

remove branchy history for qimport tests

  $ hg strip 3
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)


strip of applied mq should cleanup status file

  $ echo "mq=" >> $HGRCPATH
  $ hg up -C 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo fooagain >> bar
  $ hg ci -mf
  $ hg qimport -r tip:2

applied patches before strip

  $ hg qapplied
  2.diff
  3.diff
  4.diff

stripping revision in queue

  $ hg strip 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)

applied patches after stripping rev in queue

  $ hg qapplied
  2.diff

stripping ancestor of queue

  $ hg strip 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)

applied patches after stripping ancestor of queue

  $ hg qapplied

Verify strip protects against stripping wc parent when there are uncommitted mods

  $ echo b > b
  $ hg add b
  $ hg ci -m 'b'
  $ hg log --graph
  @  changeset:   1:7519abd79d14
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:9ab35a2d17cb
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

  $ echo c > b
  $ echo c > bar
  $ hg strip tip
  abort: local changes found
  [255]
  $ hg strip tip --keep
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  $ hg log --graph
  @  changeset:   0:9ab35a2d17cb
     tag:         tip
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  
  $ hg status
  M bar
  ? b

Strip adds, removes, modifies with --keep

  $ touch b
  $ hg add b
  $ hg commit -mb
  $ touch c

... with a clean working dir

  $ hg add c
  $ hg rm bar
  $ hg commit -mc
  $ hg status
  $ hg strip --keep tip
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  $ hg status
  ! bar
  ? c

... with a dirty working dir

  $ hg add c
  $ hg rm bar
  $ hg commit -mc
  $ hg status
  $ echo b > b
  $ echo d > d
  $ hg strip --keep tip
  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
  $ hg status
  M b
  ! bar
  ? c
  ? d
  $ cd ..

stripping many nodes on a complex graph (issue3299)

  $ hg init issue3299
  $ cd issue3299
  $ hg debugbuilddag '@a.:a@b.:b.:x<a@a.:a<b@b.:b<a@a.:a'
  $ hg strip 'not ancestors(x)'
  saved backup bundle to $TESTTMP/issue3299/.hg/strip-backup/*-backup.hg (glob)

test hg strip -B bookmark

  $ cd ..
  $ hg init bookmarks
  $ cd bookmarks
  $ hg debugbuilddag '..<2.*1/2:m<2+3:c<m+3:a<2.:b'
  $ hg bookmark -r 'a' 'todelete'
  $ hg bookmark -r 'b' 'B'
  $ hg bookmark -r 'b' 'nostrip'
  $ hg bookmark -r 'c' 'delete'
  $ hg up -C todelete
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg strip -B nostrip
  bookmark 'nostrip' deleted
  abort: empty revision set
  [255]
  $ hg strip -B todelete
  bookmark 'todelete' deleted
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/bookmarks/.hg/strip-backup/*-backup.hg (glob)
  $ hg id -ir dcbb326fdec2
  abort: unknown revision 'dcbb326fdec2'!
  [255]
  $ hg id -ir d62d843c9a01
  d62d843c9a01
  $ hg bookmarks
     B                         9:ff43616e5d0f
     delete                    6:2702dd0c91e7
  $ hg strip -B delete
  bookmark 'delete' deleted
  saved backup bundle to $TESTTMP/bookmarks/.hg/strip-backup/*-backup.hg (glob)
  $ hg id -ir 6:2702dd0c91e7
  abort: unknown revision '2702dd0c91e7'!
  [255]

  $ cd ..