view tests/test-rebase-newancestor.t @ 38486:4c0683655599

namespaces: let namespaces override singlenode() definition

Some namespaces have multiple nodes per name (meaning that their
namemap() returns multiple nodes). One such namespace is the "topics"
namespace (from the evolve repo). We also have our own internal
namespace at Google (for review units) that has multiple nodes per
name. These namespaces may not want to use the default "pick highest
revnum" resolution that we currently use when resolving a name to a
single node. As an example, they may decide that `hg co <name>` should
check out a commit that's last in some sense even if an earlier commit
had just been amended and thus had a higher revnum [1]. This patch
gives the namespace the option to continue to return multiple nodes
and to override how the best node is picked. Allowing namespaces to
override that may also be useful as an optimization (it may be cheaper
for the namespace to find just that node).

I have been arguing (in D3715) for using all the nodes returned from
namemap() when resolving the symbol to a revset, so e.g. `hg log -r
stable` would resolve to *all* nodes on stable, not just the one with
the highest revnum (except that I don't actually think we should
change it for the branch namespace because of BC). Most people seem
opposed to that. If we decide not to do it, I think we can deprecate
the namemap() function in favor of the new singlenode() (I find it
weird to have namespaces, like the branch namespace, where namemap()
isn't nodemap()'s inverse). I therefore think this patch makes sense
regardless of what we decide on that issue.


 [1] Actually, even the branch namespace would have wanted to override
     singlenode() if it had supported multiple nodes. That's because
     closes branch heads are mostly ignored, so "hg co default" will
     not check out the highest-revnum node if that's a closed head.

Differential Revision: https://phab.mercurial-scm.org/D3852

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > drawdag=$TESTDIR/drawdag.py
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
  > EOF

  $ hg init repo
  $ cd repo

  $ echo A > a
  $ echo >> a
  $ hg ci -Am A
  adding a

  $ echo B > a
  $ echo >> a
  $ hg ci -m B

  $ echo C > a
  $ echo >> a
  $ hg ci -m C

  $ hg up -q -C 0

  $ echo D >> a
  $ hg ci -Am AD
  created new head

  $ hg tglog
  @  3: 3878212183bd 'AD'
  |
  | o  2: 30ae917c0e4f 'C'
  | |
  | o  1: 0f4f7cb4f549 'B'
  |/
  o  0: 1e635d440a73 'A'
  
  $ hg rebase -s 1 -d 3
  rebasing 1:0f4f7cb4f549 "B"
  merging a
  rebasing 2:30ae917c0e4f "C"
  merging a
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/0f4f7cb4f549-82b3b163-rebase.hg

  $ hg tglog
  o  3: 25773bc4b4b0 'C'
  |
  o  2: c09015405f75 'B'
  |
  @  1: 3878212183bd 'AD'
  |
  o  0: 1e635d440a73 'A'
  

  $ cd ..


Test rebasing of merges with ancestors of the rebase destination - a situation
that often happens when trying to recover from repeated merging with a mainline
branch.

The test case creates a dev branch that contains a couple of merges from the
default branch. When rebasing to the default branch, these merges would be
merges with ancestors on the same branch. The merges _could_ contain some
interesting conflict resolutions or additional changes in the merge commit, but
that is mixed up with the actual merge stuff and there is in general no way to
separate them.

Note: The dev branch contains _no_ changes to f-default. It might be unclear
how rebasing of ancestor merges should be handled, but the current behavior
with spurious prompts for conflicts in files that didn't change seems very
wrong.

  $ hg init ancestor-merge
  $ cd ancestor-merge

  $ touch f-default
  $ hg ci -Aqm 'default: create f-default'

  $ hg branch -q dev
  $ hg ci -qm 'dev: create branch'

  $ echo stuff > f-dev
  $ hg ci -Aqm 'dev: f-dev stuff'

  $ hg up -q default
  $ echo stuff > f-default
  $ hg ci -m 'default: f-default stuff'

  $ hg up -q dev
  $ hg merge -q default
  $ hg ci -m 'dev: merge default'

  $ hg up -q default
  $ hg rm f-default
  $ hg ci -m 'default: remove f-default'

  $ hg up -q dev
  $ hg merge -q default
  $ hg ci -m 'dev: merge default'

  $ hg up -q default
  $ echo stuff > f-other
  $ hg ci -Aqm 'default: f-other stuff'

  $ hg tglog
  @  7: e08089805d82 'default: f-other stuff'
  |
  | o  6: 9455ee510502 'dev: merge default' dev
  |/|
  o |  5: 462860db70a1 'default: remove f-default'
  | |
  | o  4: 4b019212aaf6 'dev: merge default' dev
  |/|
  o |  3: f157ecfd2b6b 'default: f-default stuff'
  | |
  | o  2: ec2c14fb2984 'dev: f-dev stuff' dev
  | |
  | o  1: 1d1a643d390e 'dev: create branch' dev
  |/
  o  0: e90e8eb90b6f 'default: create f-default'
  
  $ hg clone -qU . ../ancestor-merge-2

Full rebase all the way back from branching point:

  $ hg rebase -r 'only(dev,default)' -d default --config ui.interactive=True << EOF
  > c
  > EOF
  rebasing 1:1d1a643d390e "dev: create branch"
  note: rebase of 1:1d1a643d390e created no changes to commit
  rebasing 2:ec2c14fb2984 "dev: f-dev stuff"
  rebasing 4:4b019212aaf6 "dev: merge default"
  other [source] changed f-default which local [dest] deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
  rebasing 6:9455ee510502 "dev: merge default"
  saved backup bundle to $TESTTMP/ancestor-merge/.hg/strip-backup/1d1a643d390e-43e9e04b-rebase.hg
  $ hg tglog
  o  6: fbc098e72227 'dev: merge default'
  |
  o  5: eda7b7f46f5d 'dev: merge default'
  |
  o  4: 3e075b1c0a40 'dev: f-dev stuff'
  |
  @  3: e08089805d82 'default: f-other stuff'
  |
  o  2: 462860db70a1 'default: remove f-default'
  |
  o  1: f157ecfd2b6b 'default: f-default stuff'
  |
  o  0: e90e8eb90b6f 'default: create f-default'
  
Grafty cherry picking rebasing:

  $ cd ../ancestor-merge-2

  $ hg phase -fdr0:
  $ hg rebase -r 'children(only(dev,default))' -d default --config ui.interactive=True << EOF
  > c
  > EOF
  rebasing 2:ec2c14fb2984 "dev: f-dev stuff"
  rebasing 4:4b019212aaf6 "dev: merge default"
  other [source] changed f-default which local [dest] deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
  rebasing 6:9455ee510502 "dev: merge default"
  saved backup bundle to $TESTTMP/ancestor-merge-2/.hg/strip-backup/ec2c14fb2984-62d0b222-rebase.hg
  $ hg tglog
  o  7: fbc098e72227 'dev: merge default'
  |
  o  6: eda7b7f46f5d 'dev: merge default'
  |
  o  5: 3e075b1c0a40 'dev: f-dev stuff'
  |
  o  4: e08089805d82 'default: f-other stuff'
  |
  o  3: 462860db70a1 'default: remove f-default'
  |
  o  2: f157ecfd2b6b 'default: f-default stuff'
  |
  | o  1: 1d1a643d390e 'dev: create branch' dev
  |/
  o  0: e90e8eb90b6f 'default: create f-default'
  
  $ cd ..


Test order of parents of rebased merged with un-rebased changes as p1.

  $ hg init parentorder
  $ cd parentorder
  $ touch f
  $ hg ci -Aqm common
  $ touch change
  $ hg ci -Aqm change
  $ touch target
  $ hg ci -Aqm target
  $ hg up -qr 0
  $ touch outside
  $ hg ci -Aqm outside
  $ hg merge -qr 1
  $ hg ci -m 'merge p1 3=outside p2 1=ancestor'
  $ hg par
  changeset:   4:6990226659be
  tag:         tip
  parent:      3:f59da8fc0fcf
  parent:      1:dd40c13f7a6f
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     merge p1 3=outside p2 1=ancestor
  
  $ hg up -qr 1
  $ hg merge -qr 3
  $ hg ci -qm 'merge p1 1=ancestor p2 3=outside'
  $ hg par
  changeset:   5:a57575f79074
  tag:         tip
  parent:      1:dd40c13f7a6f
  parent:      3:f59da8fc0fcf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     merge p1 1=ancestor p2 3=outside
  
  $ hg tglog
  @    5: a57575f79074 'merge p1 1=ancestor p2 3=outside'
  |\
  +---o  4: 6990226659be 'merge p1 3=outside p2 1=ancestor'
  | |/
  | o  3: f59da8fc0fcf 'outside'
  | |
  +---o  2: a60552eb93fb 'target'
  | |
  o |  1: dd40c13f7a6f 'change'
  |/
  o  0: 02f0f58d5300 'common'
  
  $ hg rebase -r 4 -d 2
  rebasing 4:6990226659be "merge p1 3=outside p2 1=ancestor"
  saved backup bundle to $TESTTMP/parentorder/.hg/strip-backup/6990226659be-4d67a0d3-rebase.hg
  $ hg tip
  changeset:   5:cca50676b1c5
  tag:         tip
  parent:      2:a60552eb93fb
  parent:      3:f59da8fc0fcf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     merge p1 3=outside p2 1=ancestor
  
  $ hg rebase -r 4 -d 2
  rebasing 4:a57575f79074 "merge p1 1=ancestor p2 3=outside"
  saved backup bundle to $TESTTMP/parentorder/.hg/strip-backup/a57575f79074-385426e5-rebase.hg
  $ hg tip
  changeset:   5:f9daf77ffe76
  tag:         tip
  parent:      2:a60552eb93fb
  parent:      3:f59da8fc0fcf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     merge p1 1=ancestor p2 3=outside
  
  $ hg tglog
  @    5: f9daf77ffe76 'merge p1 1=ancestor p2 3=outside'
  |\
  +---o  4: cca50676b1c5 'merge p1 3=outside p2 1=ancestor'
  | |/
  | o  3: f59da8fc0fcf 'outside'
  | |
  o |  2: a60552eb93fb 'target'
  | |
  o |  1: dd40c13f7a6f 'change'
  |/
  o  0: 02f0f58d5300 'common'
  
rebase of merge of ancestors

  $ hg up -qr 2
  $ hg merge -qr 3
  $ echo 'other change while merging future "rebase ancestors"' > other
  $ hg ci -Aqm 'merge rebase ancestors'
  $ hg rebase -d 5 -v
  rebasing 6:4c5f12f25ebe "merge rebase ancestors" (tip)
  resolving manifests
  removing other
  note: merging f9daf77ffe76+ and 4c5f12f25ebe using bids from ancestors a60552eb93fb and f59da8fc0fcf
  
  calculating bids for ancestor a60552eb93fb
  resolving manifests
  
  calculating bids for ancestor f59da8fc0fcf
  resolving manifests
  
  auction for merging merge bids
   other: consensus for g
  end of auction
  
  getting other
  committing files:
  other
  committing manifest
  committing changelog
  rebase merging completed
  1 changesets found
  uncompressed size of bundle content:
       199 (changelog)
       216 (manifests)
       182  other
  saved backup bundle to $TESTTMP/parentorder/.hg/strip-backup/4c5f12f25ebe-f46990e5-rebase.hg
  1 changesets found
  uncompressed size of bundle content:
       254 (changelog)
       167 (manifests)
       182  other
  adding branch
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  rebase completed
  $ hg tglog
  @  6: 113755df812b 'merge rebase ancestors'
  |
  o    5: f9daf77ffe76 'merge p1 1=ancestor p2 3=outside'
  |\
  +---o  4: cca50676b1c5 'merge p1 3=outside p2 1=ancestor'
  | |/
  | o  3: f59da8fc0fcf 'outside'
  | |
  o |  2: a60552eb93fb 'target'
  | |
  o |  1: dd40c13f7a6f 'change'
  |/
  o  0: 02f0f58d5300 'common'
  
Due to the limitation of 3-way merge algorithm (1 merge base), rebasing a merge
may include unwanted content:

  $ hg init $TESTTMP/dual-merge-base1
  $ cd $TESTTMP/dual-merge-base1
  $ hg debugdrawdag <<'EOS'
  >   F
  >  /|
  > D E
  > | |
  > B C
  > |/
  > A Z
  > |/
  > R
  > EOS
  $ hg rebase -r D+E+F -d Z
  rebasing 5:5f2c926dfecf "D" (D)
  rebasing 6:b296604d9846 "E" (E)
  rebasing 7:caa9781e507d "F" (F tip)
  abort: rebasing 7:caa9781e507d will include unwanted changes from 4:d6003a550c2c or 3:c1e6b162678d
  [255]

The warning does not get printed if there is no unwanted change detected:

  $ hg init $TESTTMP/dual-merge-base2
  $ cd $TESTTMP/dual-merge-base2
  $ hg debugdrawdag <<'EOS'
  >   D
  >  /|
  > B C
  > |/
  > A Z
  > |/
  > R
  > EOS
  $ hg rebase -r B+C+D -d Z
  rebasing 3:c1e6b162678d "B" (B)
  rebasing 4:d6003a550c2c "C" (C)
  rebasing 5:c8f78076273e "D" (D tip)
  saved backup bundle to $TESTTMP/dual-merge-base2/.hg/strip-backup/d6003a550c2c-6f1424b6-rebase.hg
  $ hg manifest -r 'desc(D)'
  B
  C
  R
  Z

The merge base could be different from old p1 (changed parent becomes new p1):

  $ hg init $TESTTMP/chosen-merge-base1
  $ cd $TESTTMP/chosen-merge-base1
  $ hg debugdrawdag <<'EOS'
  >   F
  >  /|
  > D E
  > | |
  > B C Z
  > EOS
  $ hg rebase -r D+F -d Z
  rebasing 3:004dc1679908 "D" (D)
  rebasing 5:4be4cbf6f206 "F" (F tip)
  saved backup bundle to $TESTTMP/chosen-merge-base1/.hg/strip-backup/004dc1679908-06a66a3c-rebase.hg
  $ hg manifest -r 'desc(F)'
  C
  D
  E
  Z
  $ hg log -r `hg log -r 'desc(F)' -T '{p1node}'` -T '{desc}\n'
  D

  $ hg init $TESTTMP/chosen-merge-base2
  $ cd $TESTTMP/chosen-merge-base2
  $ hg debugdrawdag <<'EOS'
  >   F
  >  /|
  > D E
  > | |
  > B C Z
  > EOS
  $ hg rebase -r E+F -d Z
  rebasing 4:974e4943c210 "E" (E)
  rebasing 5:4be4cbf6f206 "F" (F tip)
  saved backup bundle to $TESTTMP/chosen-merge-base2/.hg/strip-backup/974e4943c210-b2874da5-rebase.hg
  $ hg manifest -r 'desc(F)'
  B
  D
  E
  Z
  $ hg log -r `hg log -r 'desc(F)' -T '{p1node}'` -T '{desc}\n'
  E