tests/test-pull-update.t

commit: improve the files field of changelog for merges

Currently, the files list of merge commits repeats all the deletions
(either actual deletions, or files that got renamed) that happened
between base and p2 of the merge. If p2 is the main branch, the list
can easily be much bigger than the change being merged.

This results in various problems worth improving:
- changelog is bigger than necessary
- `hg log directory` lists many unrelated merge commits, and `hg log
  -v -r commit` frequently fills multiple screens worth of files
- it possibly slows down adjustlinkrev, by forcing it to read more
  manifests, and that function can certainly be a bottleneck
- the server side of pulls can waste a lot of time simply opening the
  filelogs for pointless files (the constant factors for opening even
  a tiny filelog is apparently pretty bad)

So stop listing such files as described in the code.  Impacted merge
commits and their descendants get a different hash than they would
have without this. This doesn't seem problematic, except for
convert. The previous commit helped with that in the hg->hg case (but
if you do svn->hg twice from scratch, hashes can still change).

The rest of the description is numbers. I don't have much to report,
because recreating the files list of existing repositories is not
easy:
- debugupgradeformat and bundle/unbundle don't recreate the list
- export/import tends to choke quickly applying patches or on
  description that contain diffs,
- merge commits from the convert extension don't have the right files
  list for reasons orthogonal to the current commit
- replaying the merge with hg update/hg merge/hg revert --all/hg
  commit can end up failing in hg revert
- I wasn't sure that using debugsetparents + debugrebuilddirstate
  would really build the right thing

I measured commit time before and after this change, in a case with no
files filtered out, several files filtered out (no difference) and 5k
files filtered out (+1% time).

Recreating the 100 more recent merges in a private repo, the
concatenated uncompressed files lists goes from 1.12MB to
0.52MB. Excluding 3 merges that are not representative, then the size
goes from 570k to 15k.
I converted part of mozilla-central, and observed file list shrinking
quite a bit too, starting at the very first merge, 733641d9feaf, going
from 550 files to 10 files (although they have relatively few merges,
so they probably wouldn't care).

Differential Revision: https://phab.mercurial-scm.org/D6613

  $ hg init t
  $ cd t
  $ echo 1 > foo
  $ hg ci -Am m
  adding foo

  $ cd ..
  $ hg clone t tt
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd tt
  $ echo 1.1 > foo
  $ hg ci -Am m

  $ cd ../t
  $ echo 1.2 > foo
  $ hg ci -Am m

Should respect config to disable dirty update
  $ hg co -qC 0
  $ echo 2 > foo
  $ hg --config commands.update.check=abort pull -u ../tt
  pulling from ../tt
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 107cefe13e42
  1 local changesets published
  abort: uncommitted changes
  [255]
  $ hg --config extensions.strip= strip --no-backup tip
  $ hg co -qC tip

Should not update to the other topological branch:

  $ hg pull -u ../tt
  pulling from ../tt
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 107cefe13e42
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  updated to "800c91d5bfc1: m"
  1 other heads for branch "default"

  $ cd ../tt

Should not update to the other branch:

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 800c91d5bfc1
  1 local changesets published
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  updated to "107cefe13e42: m"
  1 other heads for branch "default"

  $ HGMERGE=true hg merge
  merging foo
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -mm

  $ cd ../t

Should work:

  $ hg pull -u ../tt
  pulling from ../tt
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (-1 heads)
  new changesets 483b76ad4309
  1 local changesets published
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Similarity between "hg update" and "hg pull -u" in handling bookmark
====================================================================

Test that updating activates the bookmark, which matches with the
explicit destination of the update.

  $ echo 4 >> foo
  $ hg commit -m "#4"
  $ hg bookmark active-after-pull
  $ cd ../tt

(1) activating by --rev BOOKMARK

  $ hg bookmark -f active-before-pull
  $ hg bookmarks
   * active-before-pull        3:483b76ad4309

  $ hg pull -u -r active-after-pull
  pulling from $TESTTMP/t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  adding remote bookmark active-after-pull
  new changesets f815b3da6163
  1 local changesets published
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark active-after-pull)

  $ hg parents -q
  4:f815b3da6163
  $ hg bookmarks
   * active-after-pull         4:f815b3da6163
     active-before-pull        3:483b76ad4309

(discard pulled changes)

  $ hg update -q 483b76ad4309
  $ hg rollback -q

(2) activating by URL#BOOKMARK

  $ hg bookmark -f active-before-pull
  $ hg bookmarks
   * active-before-pull        3:483b76ad4309

  $ hg pull -u $TESTTMP/t#active-after-pull
  pulling from $TESTTMP/t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  adding remote bookmark active-after-pull
  new changesets f815b3da6163
  1 local changesets published
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark active-after-pull)

  $ hg parents -q
  4:f815b3da6163
  $ hg bookmarks
   * active-after-pull         4:f815b3da6163
     active-before-pull        3:483b76ad4309

(discard pulled changes)

  $ hg update -q 483b76ad4309
  $ hg rollback -q

Test that updating deactivates current active bookmark, if the
destination of the update is explicitly specified, and it doesn't
match with the name of any existing bookmarks.

  $ cd ../t
  $ hg bookmark -d active-after-pull
  $ hg branch bar -q
  $ hg commit -m "#5 (bar #1)"
  $ cd ../tt

(1) deactivating by --rev REV

  $ hg bookmark -f active-before-pull
  $ hg bookmarks
   * active-before-pull        3:483b76ad4309

  $ hg pull -u -r b5e4babfaaa7
  pulling from $TESTTMP/t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  new changesets f815b3da6163:b5e4babfaaa7
  1 local changesets published
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (leaving bookmark active-before-pull)

  $ hg parents -q
  5:b5e4babfaaa7
  $ hg bookmarks
     active-before-pull        3:483b76ad4309

(discard pulled changes)

  $ hg update -q 483b76ad4309
  $ hg rollback -q

(2) deactivating by --branch BRANCH

  $ hg bookmark -f active-before-pull
  $ hg bookmarks
   * active-before-pull        3:483b76ad4309

  $ hg pull -u -b bar
  pulling from $TESTTMP/t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  new changesets f815b3da6163:b5e4babfaaa7
  1 local changesets published
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (leaving bookmark active-before-pull)

  $ hg parents -q
  5:b5e4babfaaa7
  $ hg bookmarks
     active-before-pull        3:483b76ad4309

(discard pulled changes)

  $ hg update -q 483b76ad4309
  $ hg rollback -q

(3) deactivating by URL#ANOTHER-BRANCH

  $ hg bookmark -f active-before-pull
  $ hg bookmarks
   * active-before-pull        3:483b76ad4309

  $ hg pull -u $TESTTMP/t#bar
  pulling from $TESTTMP/t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  new changesets f815b3da6163:b5e4babfaaa7
  1 local changesets published
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (leaving bookmark active-before-pull)

  $ hg parents -q
  5:b5e4babfaaa7
  $ hg bookmarks
     active-before-pull        3:483b76ad4309

  $ cd ..