tests/test-rebase-collapse.t

filemerge: add support for partial conflict resolution by external tool

A common class of merge conflicts is in imports/#includes/etc. It's
relatively easy to write a tool that can resolve these conflicts,
perhaps by naively just unioning the statements and leaving any
cleanup to other tools to do later [1]. Such specialized tools cannot
generally resolve all conflicts in a file, of course. Let's therefore
call them "partial merge tools". Note that the internal simplemerge
algorithm is such a partial merge tool - one that only resolves
trivial "conflicts" where one side is unchanged or both sides change
in the same way.

One can also imagine having smarter language-aware partial tools that
merge the AST. It may be useful for such tools to interactively let
the user resolve any conflicts it can't resolve itself. However,
having the option of implementing it as a partial merge tool means
that the developer doesn't *need* to create a UI for it. Instead, the
user can resolve any remaining conflicts with their regular merge tool
(e.g. `:merge3` or `meld).

We don't currently have a way to let the user define such partial
merge tools. That's what this patch addresses. It lets the user
configure partial merge tools to run. Each tool can be configured to
run only on files matching certain patterns (e.g. "*.py"). The tool
takes three inputs (local, base, other) and resolves conflicts by
updating these in place. For example, let's say the inputs are these:


base:
```
import sys

def main():
  print('Hello')
```

local:
```
import os
import sys

def main():
  print('Hi')
```

other:
```
import re
import sys

def main():
  print('Howdy')
```

A partial merge tool could now resolve the conflicting imports by
replacing the import statements in *all* files by the following
snippet, while leaving the remainder of the files unchanged.

```
import os
import re
import sys
```

As a result, simplemerge and any regular merge tool that runs after
the partial merge tool(s) will consider the imports to be
non-conflicting and will only present the conflict in `main()` to the
user.

Differential Revision: https://phab.mercurial-scm.org/D12356

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

Highest phase of source commits is used:

  $ hg init phase
  $ cd phase
  $ hg debugdrawdag << 'EOF'
  >   D
  >   |
  > F C
  > | |
  > E B
  > |/
  > A
  > EOF

  $ hg phase --force --secret D

  $ cat > $TESTTMP/editor.sh <<EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > echo "edited manually" >> \$1
  > EOF
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg rebase --collapse --keepbranches -e --source B --dest F
  rebasing 1:112478962961 B "B"
  rebasing 3:26805aba1e60 C "C"
  rebasing 5:f585351a92f8 D tip "D"
  ==== before editing
  Collapsed revision
  * B
  * C
  * D
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added B
  HG: added C
  HG: added D
  ====
  saved backup bundle to $TESTTMP/phase/.hg/strip-backup/112478962961-cb2a9b47-rebase.hg

  $ hg tglogp
  o  3: 92fa5f5fe108 secret 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |
  |
  |  edited manually'
  o  2: 64a8289d2492 draft 'F'
  |
  o  1: 7fb047a69f22 draft 'E'
  |
  o  0: 426bada5c675 draft 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  E
  F

  $ cd ..


Merge gets linearized:

  $ hg init linearized-merge
  $ cd linearized-merge

  $ hg debugdrawdag << 'EOF'
  > F D
  > |/|
  > C B
  > |/
  > A
  > EOF

  $ hg phase --force --secret D
  $ hg rebase --source B --collapse --dest F
  rebasing 1:112478962961 B "B"
  rebasing 3:4e4f9194f9f1 D "D"
  saved backup bundle to $TESTTMP/linearized-merge/.hg/strip-backup/112478962961-e389075b-rebase.hg

  $ hg tglog
  o  3: 5bdc08b7da2b 'Collapsed revision
  |  * B
  |  * D'
  o  2: afc707c82df0 'F'
  |
  o  1: dc0947a82db8 'C'
  |
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  F

  $ cd ..

Custom message:

  $ hg init message
  $ cd message

  $ hg debugdrawdag << 'EOF'
  >   C
  >   |
  > D B
  > |/
  > A
  > EOF


  $ hg rebase --base B -m 'custom message'
  abort: message can only be specified with collapse
  [10]

  $ cat > $TESTTMP/checkeditform.sh <<EOF
  > env | grep HGEDITFORM
  > true
  > EOF
  $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg rebase --source B --collapse -m 'custom message' -e --dest D
  rebasing 1:112478962961 B "B"
  rebasing 3:26805aba1e60 C tip "C"
  HGEDITFORM=rebase.collapse
  saved backup bundle to $TESTTMP/message/.hg/strip-backup/112478962961-f4131707-rebase.hg

  $ hg tglog
  o  2: 2f197b9a08f3 'custom message'
  |
  o  1: b18e25de2cf5 'D'
  |
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D

  $ cd ..

Rebase and collapse - more than one external (fail):

  $ hg init multiple-external-parents
  $ cd multiple-external-parents

  $ hg debugdrawdag << 'EOF'
  >   G
  >   |\
  >   | F
  >   | |
  >   D E
  >   |\|
  > H C B
  >  \|/
  >   A
  > EOF

  $ hg rebase -s C --dest H --collapse
  abort: unable to collapse on top of 3, there is more than one external parent: 1, 6
  [20]

Rebase and collapse - E onto H:

  $ hg rebase -s E --dest H --collapse # root (E) is not a merge
  rebasing 5:49cb92066bfd E "E"
  rebasing 6:11abe3fb10b8 F "F"
  rebasing 7:64e264db77f0 G tip "G"
  saved backup bundle to $TESTTMP/multiple-external-parents/.hg/strip-backup/49cb92066bfd-ee8a8a79-rebase.hg

  $ hg tglog
  o    5: 8b2315790719 'Collapsed revision
  |\   * E
  | |  * F
  | |  * G'
  | o    4: 4e4f9194f9f1 'D'
  | |\
  o | |  3: 575c4b5ec114 'H'
  | | |
  +---o  2: dc0947a82db8 'C'
  | |
  | o  1: 112478962961 'B'
  |/
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  C
  E
  F
  H

  $ cd ..




Test that branchheads cache is updated correctly when doing a strip in which
the parent of the ancestor node to be stripped does not become a head and also,
the parent of a node that is a child of the node stripped becomes a head (node
3). The code is now much simpler and we could just test a simpler scenario
We keep it the test this way in case new complexity is injected.

Create repo b:

  $ hg init branch-heads
  $ cd branch-heads

  $ hg debugdrawdag << 'EOF'
  >   G
  >   |\
  >   | F
  >   | |
  >   D E
  >   |\|
  > H C B
  >  \|/
  >   A
  > EOF

  $ hg heads --template="{rev}:{node} {branch}\n"
  7:64e264db77f061f16d9132b70c5a58e2461fb630 default
  3:575c4b5ec114d64b681d33f8792853568bfb2b2c default

  $ cat $TESTTMP/branch-heads/.hg/cache/branch2-served
  64e264db77f061f16d9132b70c5a58e2461fb630 7
  575c4b5ec114d64b681d33f8792853568bfb2b2c o default
  64e264db77f061f16d9132b70c5a58e2461fb630 o default

  $ hg strip 4
  saved backup bundle to $TESTTMP/branch-heads/.hg/strip-backup/4e4f9194f9f1-5ec4b5e6-backup.hg

  $ cat $TESTTMP/branch-heads/.hg/cache/branch2-served
  11abe3fb10b8689b560681094b17fe161871d043 5
  dc0947a82db884575bb76ea10ac97b08536bfa03 o default
  575c4b5ec114d64b681d33f8792853568bfb2b2c o default
  11abe3fb10b8689b560681094b17fe161871d043 o default

  $ hg heads --template="{rev}:{node} {branch}\n"
  5:11abe3fb10b8689b560681094b17fe161871d043 default
  3:575c4b5ec114d64b681d33f8792853568bfb2b2c default
  2:dc0947a82db884575bb76ea10ac97b08536bfa03 default

  $ cd ..



Preserves external parent

  $ hg init external-parent
  $ cd external-parent

  $ hg debugdrawdag << 'EOF'
  >   H
  >   |\
  >   | G
  >   | |
  >   | F # F/E = F\n
  >   | |
  >   D E # D/D = D\n
  >   |\|
  > I C B
  >  \|/
  >   A
  > EOF

  $ hg rebase -s F --dest I --collapse # root (F) is not a merge
  rebasing 6:c82b08f646f1 F "F"
  file 'E' was deleted in local [dest] but was modified in other [source].
  You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.
  What do you want to do? u
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

  $ echo F > E
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase -c
  rebasing 6:c82b08f646f1 F "F"
  rebasing 7:a6db7fa104e1 G "G"
  rebasing 8:e1d201b72d91 H tip "H"
  saved backup bundle to $TESTTMP/external-parent/.hg/strip-backup/c82b08f646f1-f2721fbf-rebase.hg

  $ hg tglog
  o    6: 681daa3e686d 'Collapsed revision
  |\   * F
  | |  * G
  | |  * H'
  | | o  5: 49cb92066bfd 'E'
  | | |
  | o |  4: 09143c0bf13e 'D'
  | |\|
  o | |  3: 08ebfeb61bac 'I'
  | | |
  | o |  2: dc0947a82db8 'C'
  |/ /
  | o  1: 112478962961 'B'
  |/
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  C
  D
  E
  F
  G
  I

  $ hg up tip -q
  $ cat E
  F

  $ cd ..

Rebasing from multiple bases:

  $ hg init multiple-bases
  $ cd multiple-bases
  $ hg debugdrawdag << 'EOF'
  >   C B
  > D |/
  > |/
  > A
  > EOF
  $ hg rebase --collapse -r 'B+C' -d D
  rebasing 1:fc2b737bb2e5 B "B"
  rebasing 2:dc0947a82db8 C "C"
  saved backup bundle to $TESTTMP/multiple-bases/.hg/strip-backup/dc0947a82db8-b0c1a7ea-rebase.hg
  $ hg tglog
  o  2: 2127ae44d291 'Collapsed revision
  |  * B
  |  * C'
  o  1: b18e25de2cf5 'D'
  |
  o  0: 426bada5c675 'A'
  
  $ cd ..

With non-contiguous commits:

  $ hg init non-contiguous
  $ cd non-contiguous
  $ cat >> .hg/hgrc <<EOF
  > [experimental]
  > evolution=all
  > EOF

  $ hg debugdrawdag << 'EOF'
  > F
  > |
  > E
  > |
  > D
  > |
  > C
  > |
  > B G
  > |/
  > A
  > EOF

BROKEN: should be allowed
  $ hg rebase --collapse -r 'B+D+F' -d G
  abort: unable to collapse on top of 2, there is more than one external parent: 3, 5
  [20]
  $ cd ..


  $ hg init multiple-external-parents-2
  $ cd multiple-external-parents-2
  $ hg debugdrawdag << 'EOF'
  > D       G
  > |\     /|
  > B C   E F
  >  \|   |/
  >   \ H /
  >    \|/
  >     A
  > EOF

  $ hg rebase --collapse -d H -s 'B+F'
  abort: unable to collapse on top of 5, there is more than one external parent: 1, 3
  [20]
  $ cd ..

With internal merge:

  $ hg init internal-merge
  $ cd internal-merge

  $ hg debugdrawdag << 'EOF'
  >   E
  >   |\
  >   C D
  >   |/
  > F B
  > |/
  > A
  > EOF


  $ hg rebase -s B --collapse --dest F
  rebasing 1:112478962961 B "B"
  rebasing 3:26805aba1e60 C "C"
  rebasing 4:be0ef73c17ad D "D"
  rebasing 5:02c4367d6973 E tip "E"
  saved backup bundle to $TESTTMP/internal-merge/.hg/strip-backup/112478962961-1dfb057b-rebase.hg

  $ hg tglog
  o  2: c0512a1797b0 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |  * E'
  o  1: 8908a377a434 'F'
  |
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  F
  $ cd ..

Interactions between collapse and keepbranches
  $ hg init e
  $ cd e
  $ echo 'a' > a
  $ hg ci -Am 'A'
  adding a

  $ hg branch 'one'
  marked working directory as branch one
  (branches are permanent and global, did you want a bookmark?)
  $ echo 'b' > b
  $ hg ci -Am 'B'
  adding b

  $ hg branch 'two'
  marked working directory as branch two
  $ echo 'c' > c
  $ hg ci -Am 'C'
  adding c

  $ hg up -q 0
  $ echo 'd' > d
  $ hg ci -Am 'D'
  adding d

  $ hg tglog
  @  3: 41acb9dca9eb 'D'
  |
  | o  2: 8ac4a08debf1 'C' two
  | |
  | o  1: 1ba175478953 'B' one
  |/
  o  0: 1994f17a630e 'A'
  
  $ hg rebase --keepbranches --collapse -s 1 -d 3
  abort: cannot collapse multiple named branches
  [10]

  $ cd ..

Rebase, collapse and copies

  $ hg init copies
  $ cd copies
  $ hg unbundle "$TESTDIR/bundles/renames.hg"
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 11 changes to 7 files (+1 heads)
  new changesets f447d5abf5ea:338e84e2e558 (4 drafts)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up -q tip
  $ hg tglog
  @  3: 338e84e2e558 'move2'
  |
  o  2: 6e7340ee38c0 'move1'
  |
  | o  1: 1352765a01d4 'change'
  |/
  o  0: f447d5abf5ea 'add'
  
  $ hg rebase --collapse -d 1
  rebasing 2:6e7340ee38c0 "move1"
  merging a and d to d
  merging b and e to e
  merging c and f to f
  rebasing 3:338e84e2e558 tip "move2"
  merging f and c to c
  merging e and g to g
  saved backup bundle to $TESTTMP/copies/.hg/strip-backup/6e7340ee38c0-ef8ef003-rebase.hg
  $ hg st
  $ hg st --copies --change tip
  A d
    a
  A g
    b
  R b
  $ hg up tip -q
  $ cat c
  c
  c
  $ cat d
  a
  a
  $ cat g
  b
  b
  $ hg log -r . --template "{file_copies}\n"
  d (a)g (b)

Test collapsing a middle revision in-place

  $ hg tglog
  @  2: 64b456429f67 'Collapsed revision
  |  * move1
  |  * move2'
  o  1: 1352765a01d4 'change'
  |
  o  0: f447d5abf5ea 'add'
  
  $ hg rebase --collapse -r 1 -d 0
  abort: cannot rebase changeset, as that will orphan 1 descendants
  (see 'hg help evolution.instability')
  [10]

Test collapsing in place

  $ hg rebase --collapse -b . -d 0
  rebasing 1:1352765a01d4 "change"
  rebasing 2:64b456429f67 tip "Collapsed revision"
  saved backup bundle to $TESTTMP/copies/.hg/strip-backup/1352765a01d4-45a352ea-rebase.hg
  $ hg st --change tip --copies
  M a
  M c
  A d
    a
  A g
    b
  R b
  $ hg up tip -q
  $ cat a
  a
  a
  $ cat c
  c
  c
  $ cat d
  a
  a
  $ cat g
  b
  b
  $ cd ..


Test stripping a revision with another child

  $ hg init f
  $ cd f

  $ hg debugdrawdag << 'EOF'
  > C B
  > |/
  > A
  > EOF

  $ hg heads --template="{rev}:{node} {branch}: {desc}\n"
  2:dc0947a82db884575bb76ea10ac97b08536bfa03 default: C
  1:112478962961147124edd43549aedd1a335e44bf default: B

  $ hg strip C
  saved backup bundle to $TESTTMP/f/.hg/strip-backup/dc0947a82db8-d21b92a4-backup.hg

  $ hg tglog
  o  1: 112478962961 'B'
  |
  o  0: 426bada5c675 'A'
  


  $ hg heads --template="{rev}:{node} {branch}: {desc}\n"
  1:112478962961147124edd43549aedd1a335e44bf default: B

  $ cd ..

Test collapsing changes that add then remove a file

  $ hg init collapseaddremove
  $ cd collapseaddremove

  $ touch base
  $ hg commit -Am base
  adding base
  $ touch a
  $ hg commit -Am a
  adding a
  $ hg rm a
  $ touch b
  $ hg commit -Am b
  adding b
  $ hg book foo
  $ hg rebase -d 0 -r "1::2" --collapse -m collapsed
  rebasing 1:6d8d9f24eec3 "a"
  rebasing 2:1cc73eca5ecc foo tip "b"
  saved backup bundle to $TESTTMP/collapseaddremove/.hg/strip-backup/6d8d9f24eec3-77d3b6e2-rebase.hg
  $ hg log -G --template "{rev}: '{desc}' {bookmarks}"
  @  1: 'collapsed' foo
  |
  o  0: 'base'
  
  $ hg manifest --rev tip
  b
  base

  $ cd ..

Test that rebase --collapse will remember message after
running into merge conflict and invoking rebase --continue.

  $ hg init collapse_remember_message
  $ cd collapse_remember_message
  $ hg debugdrawdag << 'EOF'
  > C B # B/A = B\n
  > |/  # C/A = C\n
  > A
  > EOF
  $ hg rebase --collapse -m "new message" -b B -d C
  rebasing 1:81e5401e4d37 B "B"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ rm A.orig
  $ hg resolve --mark A
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 1:81e5401e4d37 B "B"
  saved backup bundle to $TESTTMP/collapse_remember_message/.hg/strip-backup/81e5401e4d37-96c3dd30-rebase.hg
  $ hg log
  changeset:   2:17186933e123
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new message
  
  changeset:   1:043039e9df84
  tag:         C
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     C
  
  changeset:   0:426bada5c675
  tag:         A
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     A
  
  $ cd ..

Test aborted editor on final message

  $ HGMERGE=:merge3
  $ export HGMERGE
  $ hg init aborted-editor
  $ cd aborted-editor
  $ hg debugdrawdag << 'EOF'
  > C   # D/A = D\n
  > |   # C/A = C\n
  > B D # B/A = B\n
  > |/  # A/A = A\n
  > A
  > EOF
  $ hg rebase --collapse -t internal:merge3 -s B -d D
  rebasing 1:f899f3910ce7 B "B"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ hg tglog
  o  3: 63668d570d21 'C'
  |
  | @  2: 82b8abf9c185 'D'
  | |
  % |  1: f899f3910ce7 'B'
  |/
  o  0: 4a2df7238c3b 'A'
  
  $ cat A
  <<<<<<< dest:             82b8abf9c185 D - test: D
  D
  ||||||| parent of source: 4a2df7238c3b A - test: A
  A
  =======
  B
  >>>>>>> source:           f899f3910ce7 B - test: B
  $ echo BC > A
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 1:f899f3910ce7 B "B"
  rebasing 3:63668d570d21 C tip "C"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ hg tglog
  %  3: 63668d570d21 'C'
  |
  | @  2: 82b8abf9c185 'D'
  | |
  o |  1: f899f3910ce7 'B'
  |/
  o  0: 4a2df7238c3b 'A'
  
  $ cat A
  <<<<<<< dest:             82b8abf9c185 D - test: D
  BC
  ||||||| parent of source: f899f3910ce7 B - test: B
  B
  =======
  C
  >>>>>>> source:           63668d570d21 C tip - test: C
  $ echo BD > A
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ HGEDITOR=false hg rebase --continue --config ui.interactive=1
  already rebased 1:f899f3910ce7 B "B" as 82b8abf9c185
  rebasing 3:63668d570d21 C tip "C"
  abort: edit failed: false exited with status 1
  [250]
  $ hg tglog
  o  3: 63668d570d21 'C'
  |
  | @  2: 82b8abf9c185 'D'
  | |
  o |  1: f899f3910ce7 'B'
  |/
  o  0: 4a2df7238c3b 'A'
  
  $ hg rebase --continue
  already rebased 1:f899f3910ce7 B "B" as 82b8abf9c185
  already rebased 3:63668d570d21 C tip "C" as 82b8abf9c185
  saved backup bundle to $TESTTMP/aborted-editor/.hg/strip-backup/f899f3910ce7-7cab5e15-rebase.hg