view tests/test-histedit-fold.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 histedit extention: Fold commands
======================================

This test file is dedicated to testing the fold command in non conflicting
case.

Initialization
---------------


  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > logt = log --template '{rev}:{node|short} {desc|firstline}\n'
  > [extensions]
  > histedit=
  > EOF


Simple folding
--------------------
  $ initrepo ()
  > {
  >     hg init r
  >     cd r
  >     for x in a b c d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  > }

  $ initrepo

log before edit
  $ hg logt --graph
  @  5:652413bf663e f
  |
  o  4:e860deea161a e
  |
  o  3:055a42cdd887 d
  |
  o  2:177f92b77385 c
  |
  o  1:d2ae7f538514 b
  |
  o  0:cb9a9f314b8b a
  

  $ hg histedit 177f92b77385 --commands - 2>&1 <<EOF | fixbundle
  > pick e860deea161a e
  > pick 652413bf663e f
  > fold 177f92b77385 c
  > pick 055a42cdd887 d
  > EOF
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

log after edit
  $ hg logt --graph
  @  4:9c277da72c9b d
  |
  o  3:6de59d13424a f
  |
  o  2:ee283cb5f2d5 e
  |
  o  1:d2ae7f538514 b
  |
  o  0:cb9a9f314b8b a
  

post-fold manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f


check histedit_source

  $ hg log --debug --rev 3
  changeset:   3:6de59d13424a8a13acd3e975514aed29dd0d9b2d
  phase:       draft
  parent:      2:ee283cb5f2d5955443f23a27b697a04339e9a39a
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    3:81eede616954057198ead0b2c73b41d1f392829a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      c f
  extra:       branch=default
  extra:       histedit_source=a4f7421b80f79fcc59fff01bcbf4a53d127dd6d3,177f92b773850b59254aa5e923436f921b55483b
  description:
  f
  ***
  c
  
  

  $ cd ..

folding and creating no new change doesn't break:
-------------------------------------------------

folded content is dropped during a merge. The folded commit should properly disapear.

  $ mkdir fold-to-empty-test
  $ cd fold-to-empty-test
  $ hg init
  $ printf "1\n2\n3\n" > file
  $ hg add file
  $ hg commit -m '1+2+3'
  $ echo 4 >> file
  $ hg commit -m '+4'
  $ echo 5 >> file
  $ hg commit -m '+5'
  $ echo 6 >> file
  $ hg commit -m '+6'
  $ hg logt --graph
  @  3:251d831eeec5 +6
  |
  o  2:888f9082bf99 +5
  |
  o  1:617f94f13c0f +4
  |
  o  0:0189ba417d34 1+2+3
  

  $ hg histedit 1 --commands - << EOF
  > pick 617f94f13c0f 1 +4
  > drop 888f9082bf99 2 +5
  > fold 251d831eeec5 3 +6
  > EOF
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging file
  warning: conflicts during merge.
  merging file incomplete! (edit conflicts, then use 'hg resolve --mark')
  Fix up the change and run hg histedit --continue
  [1]
There were conflicts, we keep P1 content. This
should effectively drop the changes from +6.
  $ hg status
  M file
  ? file.orig
  $ hg resolve -l
  U file
  $ hg revert -r 'p1()' file
  $ hg resolve --mark file
  $ hg histedit --continue
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/*-backup.hg (glob)
  $ hg logt --graph
  @  1:617f94f13c0f +4
  |
  o  0:0189ba417d34 1+2+3
  

  $ cd ..


Test fold through dropped
-------------------------


Test corner case where folded revision is separated from its parent by a
dropped revision.


  $ hg init fold-with-dropped
  $ cd fold-with-dropped
  $ printf "1\n2\n3\n" > file
  $ hg commit -Am '1+2+3'
  adding file
  $ echo 4 >> file
  $ hg commit -m '+4'
  $ echo 5 >> file
  $ hg commit -m '+5'
  $ echo 6 >> file
  $ hg commit -m '+6'
  $ hg logt -G
  @  3:251d831eeec5 +6
  |
  o  2:888f9082bf99 +5
  |
  o  1:617f94f13c0f +4
  |
  o  0:0189ba417d34 1+2+3
  
  $ hg histedit 1 --commands -  << EOF
  > pick 617f94f13c0f 1 +4
  > drop 888f9082bf99 2 +5
  > fold 251d831eeec5 3 +6
  > EOF
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging file
  warning: conflicts during merge.
  merging file incomplete! (edit conflicts, then use 'hg resolve --mark')
  Fix up the change and run hg histedit --continue
  [1]
  $ cat > file << EOF
  > 1
  > 2
  > 3
  > 4
  > 5
  > EOF
  $ hg resolve --mark file
  $ hg commit -m '+5.2'
  created new head
  $ echo 6 >> file
  $ HGEDITOR=cat hg histedit --continue
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  +4
  ***
  +5.2
  ***
  +6
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: changed file
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/fold-with-dropped/.hg/strip-backup/617f94f13c0f-backup.hg (glob)
  $ hg logt -G
  @  1:10c647b2cdd5 +4
  |
  o  0:0189ba417d34 1+2+3
  
  $ hg export tip
  # HG changeset patch
  # User test
  # Date 0 0
  #      Thu Jan 01 00:00:00 1970 +0000
  # Node ID 10c647b2cdd54db0603ecb99b2ff5ce66d5a5323
  # Parent  0189ba417d34df9dda55f88b637dcae9917b5964
  +4
  ***
  +5.2
  ***
  +6
  
  diff -r 0189ba417d34 -r 10c647b2cdd5 file
  --- a/file	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,3 +1,6 @@
   1
   2
   3
  +4
  +5
  +6
  $ cd ..


Folding with initial rename (issue3729)
---------------------------------------

  $ hg init fold-rename
  $ cd fold-rename
  $ echo a > a.txt
  $ hg add a.txt
  $ hg commit -m a
  $ hg rename a.txt b.txt
  $ hg commit -m rename
  $ echo b >> b.txt
  $ hg commit -m b

  $ hg logt --follow b.txt
  2:e0371e0426bc b
  1:1c4f440a8085 rename
  0:6c795aa153cb a

  $ hg histedit 1c4f440a8085 --commands - 2>&1 << EOF | fixbundle
  > pick 1c4f440a8085 rename
  > fold e0371e0426bc b
  > EOF
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  reverting b.txt
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg logt --follow b.txt
  1:cf858d235c76 rename
  0:6c795aa153cb a

  $ cd ..