view tests/test-empty-group.t @ 36975:795eb53f1d3e

rebase: allow in-memory merge of the working copy parent

Before this patch and when the rebase involved the working copy parent
(and thus the working copy too), we would not do in-memory rebase even
if requested to. The in-code comment explains that the reason had
something to do with avoiding an extra update, but I don't know which
update that refers to. Perhaps an earlier version of the code used to
update to the destination before rebasing even if in-memory rebase was
requested? That seems to not be done at least since aa660c1203a9
(rebase: do not bail on uncomitted changes if rebasing in-memory,
2017-12-07).

To see if this still made it slower, I create a single tiny commit on
top of one branch of the mozilla-unified repo (commit a1098c82 to be
exact) and rebased it to another branch (commit d4e9a7be). Before this
patch that took 11.8s and after this patch it took 8.6s (I only did
two runs each, but the timings were very consistent).

Differential Revision: https://phab.mercurial-scm.org/D2876

#  A          B
#
#  3  4       3
#  |\/|       |\
#  |/\|       | \
#  1  2       1  2
#  \ /        \ /
#   0          0
#
# if the result of the merge of 1 and 2
# is the same in 3 and 4, no new manifest
# will be created and the manifest group
# will be empty during the pull
#
# (plus we test a failure where outgoing
# wrongly reported the number of csets)

  $ hg init a
  $ cd a
  $ touch init
  $ hg ci -A -m 0
  adding init
  $ touch x y
  $ hg ci -A -m 1
  adding x
  adding y

  $ hg update 0
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ touch x y
  $ hg ci -A -m 2
  adding x
  adding y
  created new head

  $ hg merge 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -A -m m1

  $ hg update -C 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 2
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -A -m m2
  created new head

  $ cd ..

  $ hg clone -r 3 a b
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 3 changes to 3 files
  new changesets 5fcb73622933:d15a0c284984
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg clone -r 4 a c
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 3 changes to 3 files
  new changesets 5fcb73622933:1ec3c74fc0e0
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R a outgoing b
  comparing with b
  searching for changes
  changeset:   4:1ec3c74fc0e0
  tag:         tip
  parent:      1:79f9e10cd04e
  parent:      2:8e1bb01c1a24
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m2
  
  $ hg -R a outgoing c
  comparing with c
  searching for changes
  changeset:   3:d15a0c284984
  parent:      2:8e1bb01c1a24
  parent:      1:79f9e10cd04e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m1
  
  $ hg -R b outgoing c
  comparing with c
  searching for changes
  changeset:   3:d15a0c284984
  tag:         tip
  parent:      2:8e1bb01c1a24
  parent:      1:79f9e10cd04e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m1
  
  $ hg -R c outgoing b
  comparing with b
  searching for changes
  changeset:   3:1ec3c74fc0e0
  tag:         tip
  parent:      1:79f9e10cd04e
  parent:      2:8e1bb01c1a24
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m2
  

  $ hg -R b pull a
  pulling from a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets 1ec3c74fc0e0
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg -R c pull a
  pulling from a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets d15a0c284984
  (run 'hg heads' to see heads, 'hg merge' to merge)