view tests/test-grep.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.

  $ hg init t
  $ cd t
  $ echo import > port
  $ hg add port
  $ hg commit -m 0 -u spam -d '0 0'
  $ echo export >> port
  $ hg commit -m 1 -u eggs -d '1 0'
  $ echo export > port
  $ echo vaportight >> port
  $ echo 'import/export' >> port
  $ hg commit -m 2 -u spam -d '2 0'
  $ echo 'import/export' >> port
  $ hg commit -m 3 -u eggs -d '3 0'
  $ head -n 3 port > port1
  $ mv port1 port
  $ hg commit -m 4 -u spam -d '4 0'

pattern error

  $ hg grep '**test**'
  grep: invalid match pattern: nothing to repeat
  [1]

simple

  $ hg grep '.*'
  port:4:export
  port:4:vaportight
  port:4:import/export
  $ hg grep port port
  port:4:export
  port:4:vaportight
  port:4:import/export

simple with color

  $ hg --config extensions.color= grep --config color.mode=ansi \
  >     --color=always port port
  \x1b[0;35mport\x1b[0m\x1b[0;36m:\x1b[0m\x1b[0;32m4\x1b[0m\x1b[0;36m:\x1b[0mex\x1b[0;31;1mport\x1b[0m (esc)
  \x1b[0;35mport\x1b[0m\x1b[0;36m:\x1b[0m\x1b[0;32m4\x1b[0m\x1b[0;36m:\x1b[0mva\x1b[0;31;1mport\x1b[0might (esc)
  \x1b[0;35mport\x1b[0m\x1b[0;36m:\x1b[0m\x1b[0;32m4\x1b[0m\x1b[0;36m:\x1b[0mim\x1b[0;31;1mport\x1b[0m/export (esc)

all

  $ hg grep --traceback --all -nu port port
  port:4:4:-:spam:import/export
  port:3:4:+:eggs:import/export
  port:2:1:-:spam:import
  port:2:2:-:spam:export
  port:2:1:+:spam:export
  port:2:2:+:spam:vaportight
  port:2:3:+:spam:import/export
  port:1:2:+:eggs:export
  port:0:1:+:spam:import

other

  $ hg grep -l port port
  port:4
  $ hg grep import port
  port:4:import/export

  $ hg cp port port2
  $ hg commit -m 4 -u spam -d '5 0'

follow

  $ hg grep --traceback -f 'import\n\Z' port2
  port:0:import
  
  $ echo deport >> port2
  $ hg commit -m 5 -u eggs -d '6 0'
  $ hg grep -f --all -nu port port2
  port2:6:4:+:eggs:deport
  port:4:4:-:spam:import/export
  port:3:4:+:eggs:import/export
  port:2:1:-:spam:import
  port:2:2:-:spam:export
  port:2:1:+:spam:export
  port:2:2:+:spam:vaportight
  port:2:3:+:spam:import/export
  port:1:2:+:eggs:export
  port:0:1:+:spam:import

  $ cd ..
  $ hg init t2
  $ cd t2
  $ hg grep foobar foo
  [1]
  $ hg grep foobar
  [1]
  $ echo blue >> color
  $ echo black >> color
  $ hg add color
  $ hg ci -m 0
  $ echo orange >> color
  $ hg ci -m 1
  $ echo black > color
  $ hg ci -m 2
  $ echo orange >> color
  $ echo blue >> color
  $ hg ci -m 3
  $ hg grep orange
  color:3:orange
  $ hg grep --all orange
  color:3:+:orange
  color:2:-:orange
  color:1:+:orange


match in last "line" without newline

  $ python -c 'fp = open("noeol", "wb"); fp.write("no infinite loop"); fp.close();'
  $ hg ci -Amnoeol
  adding noeol
  $ hg grep loop
  noeol:4:no infinite loop

  $ cd ..

Issue685: trackback in grep -r after rename

Got a traceback when using grep on a single
revision with renamed files.

  $ hg init issue685
  $ cd issue685
  $ echo octarine > color
  $ hg ci -Amcolor
  adding color
  $ hg rename color colour
  $ hg ci -Am rename
  $ hg grep octarine
  colour:1:octarine
  color:0:octarine

Used to crash here

  $ hg grep -r 1 octarine
  colour:1:octarine
  $ cd ..


Issue337: test that grep follows parent-child relationships instead
of just using revision numbers.

  $ hg init issue337
  $ cd issue337

  $ echo white > color
  $ hg commit -A -m "0 white"
  adding color

  $ echo red > color
  $ hg commit -A -m "1 red"

  $ hg update 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo black > color
  $ hg commit -A -m "2 black"
  created new head

  $ hg update --clean 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo blue > color
  $ hg commit -A -m "3 blue"

  $ hg grep --all red
  color:3:-:red
  color:1:+:red

  $ cd ..

  $ hg init a
  $ cd a
  $ cp "$TESTDIR/binfile.bin" .
  $ hg add binfile.bin
  $ hg ci -m 'add binfile.bin'
  $ hg grep "MaCam" --all
  binfile.bin:0:+: Binary file matches

  $ cd ..