view tests/test-convert-hg-sink.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.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert=
  > [convert]
  > hg.saverev=False
  > EOF
  $ hg init orig
  $ cd orig
  $ echo foo > foo
  $ echo bar > bar
  $ hg ci -qAm 'add foo and bar'
  $ hg rm foo
  $ hg ci -m 'remove foo'
  $ mkdir foo
  $ echo file > foo/file
  $ hg ci -qAm 'add foo/file'
  $ hg tag some-tag
  $ hg log
  changeset:   3:593cbf6fb2b4
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag some-tag for changeset ad681a868e44
  
  changeset:   2:ad681a868e44
  tag:         some-tag
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo/file
  
  changeset:   1:cbba8ecc03b7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     remove foo
  
  changeset:   0:327daa9251fa
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo and bar
  
  $ cd ..
  $ hg convert orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  initializing destination new repository
  scanning source...
  sorting...
  converting...
  3 add foo and bar
  2 remove foo
  1 add foo/file
  0 Added tag some-tag for changeset ad681a868e44
  $ cd new
  $ hg out ../orig
  comparing with ../orig
  searching for changes
  no changes found
  [1]

dirstate should be empty:

  $ hg debugstate
  $ hg parents -q
  $ hg up -C
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg copy bar baz

put something in the dirstate:

  $ hg debugstate > debugstate
  $ grep baz debugstate
  a   0         -1 unset               baz
  copy: bar -> baz

add a new revision in the original repo

  $ cd ../orig
  $ echo baz > baz
  $ hg ci -qAm 'add baz'
  $ cd ..
  $ hg convert orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  scanning source...
  sorting...
  converting...
  0 add baz
  $ cd new
  $ hg out ../orig
  comparing with ../orig
  searching for changes
  no changes found
  [1]

dirstate should be the same (no output below):

  $ hg debugstate > new-debugstate
  $ diff debugstate new-debugstate

no copies

  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugrename baz
  baz not renamed
  $ cd ..

test tag rewriting

  $ cat > filemap <<EOF
  > exclude foo
  > EOF
  $ hg convert --filemap filemap orig new-filemap 2>&1 | grep -v 'subversion python bindings could not be loaded'
  initializing destination new-filemap repository
  scanning source...
  sorting...
  converting...
  4 add foo and bar
  3 remove foo
  2 add foo/file
  1 Added tag some-tag for changeset ad681a868e44
  0 add baz
  $ cd new-filemap
  $ hg tags
  tip                                2:3c74706b1ff8
  some-tag                           0:ba8636729451
  $ cd ..


Test cases for hg-hg roundtrip

Helper

  $ glog()
  > {
  >     hg log -G --template '{rev} {node|short} "{desc}" files: {files}\n' $*
  > }

Create a tricky source repo

  $ hg init source
  $ cd source

  $ echo 0 > 0
  $ hg ci -Aqm '0: add 0'
  $ echo a > a
  $ mkdir dir
  $ echo b > dir/b
  $ hg ci -qAm '1: add a and dir/b'
  $ echo c > dir/c
  $ hg ci -qAm '2: add dir/c'
  $ hg copy a e
  $ echo b >> b
  $ hg ci -qAm '3: copy a to e, change b'
  $ hg up -qr -3
  $ echo a >> a
  $ hg ci -qAm '4: change a'
  $ hg merge
  merging a and e to e
  2 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg copy b dir/d
  $ hg ci -qAm '5: merge 2 and 3, copy b to dir/d'
  $ echo a >> a
  $ hg ci -qAm '6: change a'

  $ hg mani
  0
  a
  b
  dir/b
  dir/c
  dir/d
  e
  $ glog
  @  6 0613c8e59a3d "6: change a" files: a
  |
  o    5 717e9b37cdb7 "5: merge 2 and 3, copy b to dir/d" files: dir/d e
  |\
  | o  4 86a55cb968d5 "4: change a" files: a
  | |
  o |  3 0e6e235919dd "3: copy a to e, change b" files: b e
  | |
  o |  2 0394b0d5e4f7 "2: add dir/c" files: dir/c
  |/
  o  1 333546584845 "1: add a and dir/b" files: a dir/b
  |
  o  0 d1a24e2ebd23 "0: add 0" files: 0
  
  $ cd ..

Convert excluding rev 0 and dir/ (and thus rev2):

  $ cat << EOF > filemap
  > exclude dir
  > EOF

  $ hg convert --filemap filemap source dest --config convert.hg.revs=1::
  initializing destination dest repository
  scanning source...
  sorting...
  converting...
  5 1: add a and dir/b
  4 2: add dir/c
  3 3: copy a to e, change b
  2 4: change a
  1 5: merge 2 and 3, copy b to dir/d
  0 6: change a

Verify that conversion skipped rev 2:

  $ glog -R dest
  o  4 78814e84a217 "6: change a" files: a
  |
  o    3 f7cff662c5e5 "5: merge 2 and 3, copy b to dir/d" files: e
  |\
  | o  2 ab40a95b0072 "4: change a" files: a
  | |
  o |  1 bd51f17597bf "3: copy a to e, change b" files: b e
  |/
  o  0 a4a1dae0fe35 "1: add a and dir/b" files: 0 a
  

Verify mapping correct in both directions:

  $ cat source/.hg/shamap
  a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5 333546584845f70c4cfecb992341aaef0e708166
  bd51f17597bf32268e68a560b206898c3960cda2 0e6e235919dd8e9285ba8eb5adf703af9ad99378
  ab40a95b00725307e79c2fd271000aa8af9759f4 86a55cb968d51770cba2a1630d6cc637b574580a
  f7cff662c5e581e6f3f1a85ffdd2bcb35825f6ba 717e9b37cdb7eb9917ca8e30aa3f986e6d5b177d
  78814e84a217894517c2de392b903ed05e6871a4 0613c8e59a3ddb9789072ef52f1ed13496489bb4
  $ cat dest/.hg/shamap
  333546584845f70c4cfecb992341aaef0e708166 a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5
  0394b0d5e4f761ced559fd0bbdc6afc16cb3f7d1 a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5
  0e6e235919dd8e9285ba8eb5adf703af9ad99378 bd51f17597bf32268e68a560b206898c3960cda2
  86a55cb968d51770cba2a1630d6cc637b574580a ab40a95b00725307e79c2fd271000aa8af9759f4
  717e9b37cdb7eb9917ca8e30aa3f986e6d5b177d f7cff662c5e581e6f3f1a85ffdd2bcb35825f6ba
  0613c8e59a3ddb9789072ef52f1ed13496489bb4 78814e84a217894517c2de392b903ed05e6871a4

Verify meta data converted correctly:

  $ hg -R dest log -r 1 --debug -p --git
  changeset:   1:bd51f17597bf32268e68a560b206898c3960cda2
  phase:       draft
  parent:      0:a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    1:040c72ed9b101773c24ac314776bfc846943781f
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      b e
  extra:       branch=default
  description:
  3: copy a to e, change b
  
  
  diff --git a/b b/b
  new file mode 100644
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +b
  diff --git a/a b/e
  copy from a
  copy to e
  
Verify files included and excluded correctly:

  $ hg -R dest manifest -r tip
  0
  a
  b
  e


Make changes in dest and convert back:

  $ hg -R dest up -q
  $ echo dest > dest/dest
  $ hg -R dest ci -Aqm 'change in dest'
  $ hg -R dest tip
  changeset:   5:a2e0e3cc6d1d
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change in dest
  

(converting merges back after using a filemap will probably cause chaos so we
exclude merges.)

  $ hg convert dest source --config convert.hg.revs='!merge()'
  scanning source...
  sorting...
  converting...
  0 change in dest

Verify the conversion back:

  $ hg -R source log --debug -r tip
  changeset:   7:e6d364a69ff1248b2099e603b0c145504cade6f0
  tag:         tip
  phase:       draft
  parent:      6:0613c8e59a3ddb9789072ef52f1ed13496489bb4
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    7:aa3e9542f3b76d4f1f1b2e9c7ce9dbb48b6a95ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      dest
  extra:       branch=default
  description:
  change in dest
  
  
Files that had been excluded are still present:

  $ hg -R source manifest -r tip
  0
  a
  b
  dest
  dir/b
  dir/c
  dir/d
  e

More source changes

  $ cd source
  $ echo 1 >> a
  $ hg ci -m '8: source first branch'
  created new head
  $ hg up -qr -2
  $ echo 2 >> a
  $ hg ci -m '9: source second branch'
  $ hg merge -q --tool internal:local
  $ hg ci -m '10: source merge'
  $ echo >> a
  $ hg ci -m '11: source change'

  $ hg mani
  0
  a
  b
  dest
  dir/b
  dir/c
  dir/d
  e

  $ glog -r 6:
  @  11 0c8927d1f7f4 "11: source change" files: a
  |
  o    10 9ccb7ee8d261 "10: source merge" files: a
  |\
  | o  9 f131b1518dba "9: source second branch" files: a
  | |
  o |  8 669cf0e74b50 "8: source first branch" files: a
  | |
  | o  7 e6d364a69ff1 "change in dest" files: dest
  |/
  o  6 0613c8e59a3d "6: change a" files: a
  |
  $ cd ..

  $ hg convert --filemap filemap source dest --config convert.hg.revs=3:
  scanning source...
  sorting...
  converting...
  3 8: source first branch
  2 9: source second branch
  1 10: source merge
  0 11: source change

  $ glog -R dest
  o  9 8432d597b263 "11: source change" files: a
  |
  o    8 632ffacdcd6f "10: source merge" files: a
  |\
  | o  7 049cfee90ee6 "9: source second branch" files: a
  | |
  o |  6 9b6845e036e5 "8: source first branch" files: a
  | |
  | @  5 a2e0e3cc6d1d "change in dest" files: dest
  |/
  o  4 78814e84a217 "6: change a" files: a
  |
  o    3 f7cff662c5e5 "5: merge 2 and 3, copy b to dir/d" files: e
  |\
  | o  2 ab40a95b0072 "4: change a" files: a
  | |
  o |  1 bd51f17597bf "3: copy a to e, change b" files: b e
  |/
  o  0 a4a1dae0fe35 "1: add a and dir/b" files: 0 a
  
  $ cd ..