view tests/test-commit-unresolved.t @ 42621:99ebde4fec99

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

#testcases abortcommand abortflag
#if abortflag
  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > abort = merge --abort
  > EOF
#endif

  $ addcommit () {
  >     echo $1 > $1
  >     hg add $1
  >     hg commit -d "${2} 0" -m $1
  > }

  $ commit () {
  >     hg commit -d "${2} 0" -m $1
  > }

  $ hg init a
  $ cd a
  $ addcommit "A" 0
  $ addcommit "B" 1
  $ echo "C" >> A
  $ commit "C" 2

  $ hg update -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo "D" >> A
  $ commit "D" 3
  created new head

State before the merge

  $ hg status
  $ hg id
  e45016d2b3d3 tip
  $ hg summary
  parent: 3:e45016d2b3d3 tip
   D
  branch: default
  commit: (clean)
  update: 2 new changesets, 2 branch heads (merge)
  phases: 4 draft

Testing the abort functionality first in case of conflicts

  $ hg abort
  abort: no merge in progress (abortflag !)
  abort: no operation in progress (abortcommand !)
  [255]

  $ hg merge
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]

  $ hg merge --abort e4501
  abort: cannot specify a node with --abort
  [255]
  $ hg merge --abort --rev e4501
  abort: cannot specify both --rev and --abort
  [255]

#if abortcommand
when in dry-run mode
  $ hg abort --dry-run
  merge in progress, will be aborted
#endif

  $ hg abort
  aborting the merge, updating back to e45016d2b3d3
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

Checking that we got back in the same state

  $ hg status
  ? A.orig
  $ hg id
  e45016d2b3d3 tip
  $ hg summary
  parent: 3:e45016d2b3d3 tip
   D
  branch: default
  commit: 1 unknown (clean)
  update: 2 new changesets, 2 branch heads (merge)
  phases: 4 draft

Merging a conflict araises

  $ hg merge
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]

Correct the conflict without marking the file as resolved

  $ echo "ABCD" > A
  $ hg commit -m "Merged"
  abort: unresolved merge conflicts (see 'hg help resolve')
  [255]

Mark the conflict as resolved and commit

  $ hg resolve -m A
  (no more unresolved files)
  $ hg commit -m "Merged"

Test that if a file is removed but not marked resolved, the commit still fails
(issue4972)

  $ hg up ".^"
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 2
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg rm --force A
  $ hg commit -m merged
  abort: unresolved merge conflicts (see 'hg help resolve')
  [255]

  $ hg resolve -ma
  (no more unresolved files)
  $ hg commit -m merged
  created new head

Testing the abort functionality in case of no conflicts

  $ hg update -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ addcommit "E" 4
  created new head
  $ hg id
  68352a18a7c4 tip

  $ hg merge -r 4
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg merge --preview --abort
  abort: cannot specify --preview with --abort
  [255]

  $ hg abort
  aborting the merge, updating back to 68352a18a7c4
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg id
  68352a18a7c4 tip

  $ cd ..