annotate tests/test-treediscovery.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.

  $ "$TESTDIR/hghave" killdaemons || exit 80

Tests discovery against servers without getbundle support:

  $ CAP=getbundle
  $ . "$TESTDIR/notcapable"
  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > logtemplate="{rev} {node|short}: {desc} {branches}\n"
  > EOF

Setup HTTP server control:

  $ remote=http://localhost:$HGPORT/
  $ export remote
  $ tstart() {
  >   echo '[web]' > $1/.hg/hgrc
  >   echo 'push_ssl = false' >> $1/.hg/hgrc
  >   echo 'allow_push = *' >> $1/.hg/hgrc
  >   hg serve -R $1 -p $HGPORT -d --pid-file=hg.pid -E errors.log
  >   cat hg.pid >> $DAEMON_PIDS
  > }
  $ tstop() {
  >   "$TESTDIR/killdaemons.py" $DAEMON_PIDS
  > }

Both are empty:

  $ hg init empty1
  $ hg init empty2
  $ tstart empty2
  $ hg incoming -R empty1 $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg outgoing -R empty1 $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg pull -R empty1 $remote
  pulling from http://localhost:$HGPORT/
  no changes found
  $ hg push -R empty1 $remote
  pushing to http://localhost:$HGPORT/
  no changes found
  [1]
  $ tstop

Base repo:

  $ hg init main
  $ cd main
  $ hg debugbuilddag -mo '+2:tbase @name1 +3:thead1 <tbase @name2 +4:thead2 @both /thead1 +2:tmaintip'
  $ hg log -G
  o  11 a19bfa7e7328: r11 both
  |
  o  10 8b6bad1512e1: r10 both
  |
  o    9 025829e08038: r9 both
  |\
  | o  8 d8f638ac69e9: r8 name2
  | |
  | o  7 b6b4d315a2ac: r7 name2
  | |
  | o  6 6c6f5d5f3c11: r6 name2
  | |
  | o  5 70314b29987d: r5 name2
  | |
  o |  4 e71dbbc70e03: r4 name1
  | |
  o |  3 2c8d5d5ec612: r3 name1
  | |
  o |  2 a7892891da29: r2 name1
  |/
  o  1 0019a3b924fd: r1
  |
  o  0 d57206cc072a: r0
  
  $ cd ..
  $ tstart main

Full clone:

  $ hg clone main full
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd full
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is empty:

  $ cd empty1
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  0 d57206cc072a: r0 
  1 0019a3b924fd: r1 
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  5 70314b29987d: r5 name2
  6 6c6f5d5f3c11: r6 name2
  7 b6b4d315a2ac: r7 name2
  8 d8f638ac69e9: r8 name2
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 12 changesets with 24 changes to 2 files
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is subset:

  $ hg clone main subset --rev name2 ; cd subset
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Remote is empty:

  $ tstop ; tstart empty2
  $ cd main
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  0 d57206cc072a: r0 
  1 0019a3b924fd: r1 
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  5 70314b29987d: r5 name2
  6 6c6f5d5f3c11: r6 name2
  7 b6b4d315a2ac: r7 name2
  8 d8f638ac69e9: r8 name2
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 12 changesets with 24 changes to 2 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is superset:

  $ tstop
  $ hg clone main subset2 --rev name2
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ tstart subset2
  $ cd main
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: push creates new remote branches: both, name1!
  (use 'hg push --new-branch' to create new remote branches)
  [255]
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 6 changesets with 12 changes to 2 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Partial pull:

  $ tstop ; tstart main
  $ hg clone $remote partial --rev name2
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd partial
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg incoming $remote --rev name1
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  $ hg pull $remote --rev name1
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 6 changes to 2 files (+1 heads)
  (run 'hg heads' to see heads)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ cd ..

Both have new stuff in new named branches:

  $ tstop
  $ hg clone main repo1a --rev name1 -q
  $ hg clone repo1a repo1b -q
  $ hg clone main repo2a --rev name2 -q
  $ hg clone repo2a repo2b -q
  $ tstart repo1a

  $ cd repo2a
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  2 70314b29987d: r5 name2
  3 6c6f5d5f3c11: r6 name2
  4 b6b4d315a2ac: r7 name2
  5 d8f638ac69e9: r8 name2
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 4 changesets with 8 changes to 2 files (+1 heads)
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 6 changes to 2 files (+1 heads)
  (run 'hg heads' to see heads)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

  $ tstop ; tstart repo1b
  $ cd repo2b
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  2 70314b29987d: r5 name2
  3 6c6f5d5f3c11: r6 name2
  4 b6b4d315a2ac: r7 name2
  5 d8f638ac69e9: r8 name2
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 6 changes to 2 files (+1 heads)
  (run 'hg heads' to see heads)
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 4 changesets with 8 changes to 2 files (+1 heads)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Both have new stuff in existing named branches:

  $ tstop
  $ rm -r repo1a repo1b repo2a repo2b
  $ hg clone main repo1a --rev 3 --rev 8 -q
  $ hg clone repo1a repo1b -q
  $ hg clone main repo2a --rev 4 --rev 7 -q
  $ hg clone repo2a repo2b -q
  $ tstart repo1a

  $ cd repo2a
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  8 d8f638ac69e9: r8 name2
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  4 e71dbbc70e03: r4 name1
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 2 changes to 2 files
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

  $ tstop ; tstart repo1b
  $ cd repo2b
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  8 d8f638ac69e9: r8 name2
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  4 e71dbbc70e03: r4 name1
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  (run 'hg update' to get a working copy)
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 2 changes to 2 files
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

  $ tstop