tests/test-no-symlinks.t

perf: add perfchangegroupchangelog command

This command can be used for testing the performance of producing the
changelog portion of a changegroup.

We could use additional perf* commands for testing other parts of
changegroup. Those can be written another time, when they are needed.
(And those may want to refactor the changegroup generation API so code
can be reused.) Speaking of code reuse, yes, this command does reinvent
a small wheel. I didn't want to scope bloat to change the changegroup
API because that will invite bikeshedding.

#require no-symlink

# The following script was used to create the bundle:
#
# hg init symlinks
# cd symlinks
# echo a > a
# mkdir d
# echo b > d/b
# ln -s a a.lnk
# ln -s d/b d/b.lnk
# hg ci -Am t
# hg bundle --base null ../test-no-symlinks.hg

Extract a symlink on a platform not supporting them

  $ hg init t
  $ cd t
  $ hg pull -q "$TESTDIR/bundles/test-no-symlinks.hg"
  $ hg update
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat a.lnk && echo
  a
  $ cat d/b.lnk && echo
  d/b

Copy a symlink and move another

  $ hg copy a.lnk d/a2.lnk
  $ hg mv d/b.lnk b2.lnk
  $ hg ci -Am copy
  $ cat d/a2.lnk && echo
  a
  $ cat b2.lnk && echo
  d/b

Bundle and extract again

  $ hg bundle --base null ../symlinks.hg
  2 changesets found
  $ cd ..
  $ hg init t2
  $ cd t2
  $ hg pull ../symlinks.hg
  pulling from ../symlinks.hg
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 6 changes to 6 files
  (run 'hg update' to get a working copy)
  $ hg update
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat a.lnk && echo
  a
  $ cat d/a2.lnk && echo
  a
  $ cat b2.lnk && echo
  d/b