tests/test-module-imports.t

revlog: move file writing to a separate function

Moves the code that actually writes to a file to a separate function in
revlog.py. This allows extensions to intercept and use the data being written to
disk. For example, an extension might want to replicate these writes elsewhere.

When cloning the Mercurial repo on /dev/shm with --pull, I see about a 0.3% perf change.
It goes from 28.2 to 28.3 seconds.

This code uses the ast module, which was new in 2.6, so we'll skip
this test on anything earlier.
  $ python -c 'import sys ; assert sys.version_info >= (2, 6)' || exit 80

  $ import_checker="$TESTDIR"/../contrib/import-checker.py
Run the doctests from the import checker, and make sure
it's working correctly.
  $ TERM=dumb
  $ export TERM
  $ python -m doctest $import_checker

  $ cd "$TESTDIR"/..
  $ if hg identify -q > /dev/null 2>&1; then :
  > else
  >     echo "skipped: not a Mercurial working dir" >&2
  >     exit 80
  > fi

There are a handful of cases here that require renaming a module so it
doesn't overlap with a stdlib module name. There are also some cycles
here that we should still endeavor to fix, and some cycles will be
hidden by deduplication algorithm in the cycle detector, so fixing
these may expose other cycles.

  $ hg locate 'mercurial/**.py' | xargs python "$import_checker"
  mercurial/dispatch.py mixed stdlib and relative imports:
     commands, error, extensions, fancyopts, hg, hook, util
  mercurial/fileset.py mixed stdlib and relative imports:
     error, merge, parser, util
  mercurial/revset.py mixed stdlib and relative imports:
     discovery, error, hbisect, parser, phases, util
  mercurial/templater.py mixed stdlib and relative imports:
     config, error, parser, templatefilters, util
  mercurial/ui.py mixed stdlib and relative imports:
     config, error, formatter, scmutil, util
  Import cycle: mercurial.cmdutil -> mercurial.subrepo -> mercurial.cmdutil
  Import cycle: mercurial.repoview -> mercurial.revset -> mercurial.repoview
  Import cycle: mercurial.fileset -> mercurial.merge -> mercurial.subrepo -> mercurial.match -> mercurial.fileset
  Import cycle: mercurial.filemerge -> mercurial.match -> mercurial.fileset -> mercurial.merge -> mercurial.filemerge