tests/test-generaldelta.t

convert: add support to detect git renames and copies

Git is fairly unique among VCSes in that it doesn't record copies and renames,
instead choosing to detect them on the fly. Since Mercurial expects copies and
renames to be recorded, it can be valuable to preserve this history while
converting a Git repository to Mercurial. This patch adds a new convert option,
called 'convert.git.similarity', which determines how similar files must be to
be treated as renames or copies.

Check whether size of generaldelta revlog is not bigger than its
regular equivalent. Test would fail if generaldelta was naive
implementation of parentdelta: third manifest revision would be fully
inserted due to big distance from its paren revision (zero).

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ echo bar > bar
  $ hg commit -q -Am boo
  $ hg clone --pull . ../gdrepo -q --config format.generaldelta=yes
  $ for r in 1 2 3; do
  >   echo $r > foo
  >   hg commit -q -m $r
  >   hg up -q -r 0
  >   hg pull . -q -r $r -R ../gdrepo
  > done

  $ cd ..
  >>> import os
  >>> regsize = os.stat("repo/.hg/store/00manifest.i").st_size
  >>> gdsize = os.stat("gdrepo/.hg/store/00manifest.i").st_size
  >>> if regsize < gdsize:
  ...     print 'generaldata increased size of manifest'