tests/test-pull-r.t

revlog: change generaldelta delta parent heuristic

The old generaldelta heuristic was "if p1 (or p2) was closer than the last full text,
use it, otherwise use prev". This was problematic when a repo contained multiple
branches that were very different. If commits to branch A were pushed, and the
last full text was branch B, it would generate a fulltext. Then if branch B was
pushed, it would generate another fulltext. The problem is that the last
fulltext (and delta'ing against `prev` in general) has no correlation with the
contents of the incoming revision, and therefore will always have degenerate
cases.

According to the blame, that algorithm was chosen to minimize the chain length.
Since there is already code that protects against that (the delta-vs-fulltext
code), and since it has been improved since the original generaldelta algorithm
went in (2011), I believe the chain length criteria will still be preserved.

The new algorithm always diffs against p1 (or p2 if it's closer), unless the
resulting delta will fail the delta-vs-fulltext check, in which case we delta
against prev.

Some before and after stats on manifest.d size.

internal large repo
old heuristic - 2.0 GB
new heuristic - 1.2 GB

mozilla-central
old heuristic - 242 MB
new heuristic - 261 MB

The regression in mozilla central is due to the new heuristic choosing p2r as
the delta when it's closer to the tip. Switching the algorithm to always prefer
p1r brings the size back down (242 MB). This is result of the way in which
mozilla does merges and pushes, and the result could easily swing the other
direction in other repos (depending on if they merge X into Y or Y into X), but
will never be as degenerate as before.

I future patch will address the regression by introducing an optional, even more
aggressive delta heuristic which will knock the mozilla manifest size down
dramatically.

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ hg ci -qAm 'add foo'
  $ echo >> foo
  $ hg ci -m 'change foo'
  $ hg up -qC 0
  $ echo bar > bar
  $ hg ci -qAm 'add bar'

  $ hg log
  changeset:   2:effea6de0384
  tag:         tip
  parent:      0:bbd179dfa0a7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  changeset:   1:ed1b79f46b9a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change foo
  
  changeset:   0:bbd179dfa0a7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  
  $ cd ..

don't show "(+1 heads)" message when pulling closed head

  $ hg clone -q repo repo2
  $ hg clone -q repo2 repo3
  $ cd repo2
  $ hg up -q 0
  $ echo hello >> foo
  $ hg ci -mx1
  created new head
  $ hg ci -mx2 --close-branch
  $ cd ../repo3
  $ hg heads -q --closed
  2:effea6de0384
  1:ed1b79f46b9a
  $ hg pull
  pulling from $TESTTMP/repo2 (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg heads -q --closed
  4:00cfe9073916
  2:effea6de0384
  1:ed1b79f46b9a

  $ cd ..

  $ hg init copy
  $ cd copy

Pull a missing revision:

  $ hg pull -qr missing ../repo
  abort: unknown revision 'missing'!
  [255]

Pull multiple revisions with update:

  $ hg pull -qu -r 0 -r 1 ../repo
  $ hg -q parents
  0:bbd179dfa0a7
  $ hg rollback
  repository tip rolled back to revision -1 (undo pull)
  working directory now based on revision -1

  $ hg pull -qr 0 ../repo
  $ hg log
  changeset:   0:bbd179dfa0a7
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  
  $ hg pull -qr 1 ../repo
  $ hg log
  changeset:   1:ed1b79f46b9a
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change foo
  
  changeset:   0:bbd179dfa0a7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  

This used to abort: received changelog group is empty:

  $ hg pull -qr 1 ../repo

Test race condition with -r and -U (issue4707)

We pull '-U -r <name>' and the name change right after/during the changegroup emission.
We use http because http is better is our racy-est option.


  $ echo babar > ../repo/jungle
  $ cat <<EOF > ../repo/.hg/hgrc
  > [hooks]
  > outgoing.makecommit = hg ci -Am 'racy commit'; echo committed in pull-race
  > EOF
  $ hg -R ../repo serve -p $HGPORT2 -d --pid-file=../repo.pid
  $ cat ../repo.pid >> $DAEMON_PIDS
  $ hg pull --rev default --update http://localhost:$HGPORT2/
  pulling from http://localhost:$HGPORT2/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G
  @  changeset:   2:effea6de0384
  |  tag:         tip
  |  parent:      0:bbd179dfa0a7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     add bar
  |
  | o  changeset:   1:ed1b79f46b9a
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     change foo
  |
  o  changeset:   0:bbd179dfa0a7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     add foo
  

  $ cd ..