rebase: allow collapsing branches in place (issue3111)
We allow rebase plus collapse, but not collapse only? I imagine people would
rebase first then collapse once they are sure the rebase is correct and it is
the right time to finish it.
I was reluctant to submit this patch for reasons detailed below, but it
improves rebase --collapse usefulness so much it is worth the ugliness.
The fix is ugly because we should be fixing the collapse code path rather than
the merge. Collapsing by merging changesets repeatedly is inefficient compared
to what commit --amend does: commitctx(), update, strip. The problem with the
latter is, to generate the synthetic changeset, copy records are gathered with
copies.pathcopies(). copies.pathcopies() is still implemented with merging in
mind and discards information like file replaced by the copy of another,
criss-cross copies and so forth. I believe this information should not be lost,
even if we decide not to interpret it fully later, at merge time.
The second issue with improving rebase --collapse is the option should not be
there to begin with. Rebasing and collapsing are orthogonal and a dedicated
command would probably enable a better, simpler ui. We should avoid advertizing
rebase --collapse, but with this fix it becomes the best shipped solution to
collapse changesets.
And for the record, available techniques are:
- revert + commit + strip: lose copies
- mq/qfold: repeated patching() (mostly correct, fragile)
- rebase: repeated merges (mostly correct, fragile)
- collapse: revert + tag rewriting wizardry, lose copies
- histedit: repeated patching() (mostly correct, fragile)
- amend: copies.pathcopies() + commitctx() + update + strip
$ cat >> $HGRCPATH <<EOF
> [extensions]
> graphlog=
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: '{desc}' {branches}\n"
> tglogp = log -G --template "{rev}:{phase} '{desc}' {branches}\n"
> EOF
Create repo a:
$ hg init a
$ cd a
$ hg unbundle "$TESTDIR/bundles/rebase.hg"
adding changesets
adding manifests
adding file changes
added 8 changesets with 7 changes to 7 files (+2 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tglog
@ 7: 'H'
|
| o 6: 'G'
|/|
o | 5: 'F'
| |
| o 4: 'E'
|/
| o 3: 'D'
| |
| o 2: 'C'
| |
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Rebasing B onto H and collapsing changesets with different phases:
$ hg clone -q -u 3 a a1
$ cd a1
$ hg phase --force --secret 3
$ hg rebase --collapse --keepbranches
saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob)
$ hg tglogp
@ 5:secret 'Collapsed revision
| * B
| * C
| * D'
o 4:draft 'H'
|
| o 3:draft 'G'
|/|
o | 2:draft 'F'
| |
| o 1:draft 'E'
|/
o 0:draft 'A'
$ hg manifest
A
B
C
D
F
H
$ cd ..
Rebasing E onto H:
$ hg clone -q -u . a a2
$ cd a2
$ hg phase --force --secret 6
$ hg rebase --source 4 --collapse
saved backup bundle to $TESTTMP/a2/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 6: 'Collapsed revision
| * E
| * G'
o 5: 'H'
|
o 4: 'F'
|
| o 3: 'D'
| |
| o 2: 'C'
| |
| o 1: 'B'
|/
o 0: 'A'
$ hg manifest
A
E
F
H
$ cd ..
Rebasing G onto H with custom message:
$ hg clone -q -u . a a3
$ cd a3
$ hg rebase --base 6 -m 'custom message'
abort: message can only be specified with collapse
[255]
$ hg rebase --source 4 --collapse -m 'custom message'
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 6: 'custom message'
|
o 5: 'H'
|
o 4: 'F'
|
| o 3: 'D'
| |
| o 2: 'C'
| |
| o 1: 'B'
|/
o 0: 'A'
$ hg manifest
A
E
F
H
$ cd ..
Create repo b:
$ hg init b
$ cd b
$ echo A > A
$ hg ci -Am A
adding A
$ echo B > B
$ hg ci -Am B
adding B
$ hg up -q 0
$ echo C > C
$ hg ci -Am C
adding C
created new head
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo D > D
$ hg ci -Am D
adding D
$ hg up -q 1
$ echo E > E
$ hg ci -Am E
adding E
created new head
$ echo F > F
$ hg ci -Am F
adding F
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m G
$ hg up -q 0
$ echo H > H
$ hg ci -Am H
adding H
created new head
$ hg tglog
@ 7: 'H'
|
| o 6: 'G'
| |\
| | o 5: 'F'
| | |
| | o 4: 'E'
| | |
| o | 3: 'D'
| |\|
| o | 2: 'C'
|/ /
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Rebase and collapse - more than one external (fail):
$ hg clone -q -u . b b1
$ cd b1
$ hg rebase -s 2 --collapse
abort: unable to collapse, there is more than one external parent
[255]
Rebase and collapse - E onto H:
$ hg rebase -s 4 --collapse
saved backup bundle to $TESTTMP/b1/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 5: 'Collapsed revision
|\ * E
| | * F
| | * G'
| o 4: 'H'
| |
o | 3: 'D'
|\ \
| o | 2: 'C'
| |/
o / 1: 'B'
|/
o 0: 'A'
$ hg manifest
A
B
C
D
E
F
H
$ cd ..
Create repo c:
$ hg init c
$ cd c
$ echo A > A
$ hg ci -Am A
adding A
$ echo B > B
$ hg ci -Am B
adding B
$ hg up -q 0
$ echo C > C
$ hg ci -Am C
adding C
created new head
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo D > D
$ hg ci -Am D
adding D
$ hg up -q 1
$ echo E > E
$ hg ci -Am E
adding E
created new head
$ echo F > E
$ hg ci -m 'F'
$ echo G > G
$ hg ci -Am G
adding G
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m H
$ hg up -q 0
$ echo I > I
$ hg ci -Am I
adding I
created new head
$ hg tglog
@ 8: 'I'
|
| o 7: 'H'
| |\
| | o 6: 'G'
| | |
| | o 5: 'F'
| | |
| | o 4: 'E'
| | |
| o | 3: 'D'
| |\|
| o | 2: 'C'
|/ /
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Rebase and collapse - E onto I:
$ hg clone -q -u . c c1
$ cd c1
$ hg rebase -s 4 --collapse
merging E
saved backup bundle to $TESTTMP/c1/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 5: 'Collapsed revision
|\ * E
| | * F
| | * G
| | * H'
| o 4: 'I'
| |
o | 3: 'D'
|\ \
| o | 2: 'C'
| |/
o / 1: 'B'
|/
o 0: 'A'
$ hg manifest
A
B
C
D
E
G
I
$ cat E
F
$ cd ..
Create repo d:
$ hg init d
$ cd d
$ echo A > A
$ hg ci -Am A
adding A
$ echo B > B
$ hg ci -Am B
adding B
$ echo C > C
$ hg ci -Am C
adding C
$ hg up -q 1
$ echo D > D
$ hg ci -Am D
adding D
created new head
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m E
$ hg up -q 0
$ echo F > F
$ hg ci -Am F
adding F
created new head
$ hg tglog
@ 5: 'F'
|
| o 4: 'E'
| |\
| | o 3: 'D'
| | |
| o | 2: 'C'
| |/
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Rebase and collapse - B onto F:
$ hg clone -q -u . d d1
$ cd d1
$ hg rebase -s 1 --collapse
saved backup bundle to $TESTTMP/d1/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 2: 'Collapsed revision
| * B
| * C
| * D
| * E'
o 1: 'F'
|
o 0: 'A'
$ hg manifest
A
B
C
D
F
Interactions between collapse and keepbranches
$ cd ..
$ hg init e
$ cd e
$ echo 'a' > a
$ hg ci -Am 'A'
adding a
$ hg branch '1'
marked working directory as branch 1
(branches are permanent and global, did you want a bookmark?)
$ echo 'b' > b
$ hg ci -Am 'B'
adding b
$ hg branch '2'
marked working directory as branch 2
(branches are permanent and global, did you want a bookmark?)
$ 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: 'D'
|
| o 2: 'C' 2
| |
| o 1: 'B' 1
|/
o 0: 'A'
$ hg rebase --keepbranches --collapse -s 1 -d 3
abort: cannot collapse multiple named branches
[255]
$ repeatchange() {
> hg checkout $1
> hg cp d z
> echo blah >> z
> hg commit -Am "$2" --user "$3"
> }
$ repeatchange 3 "E" "user1"
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ repeatchange 3 "E" "user2"
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
created new head
$ hg tglog
@ 5: 'E'
|
| o 4: 'E'
|/
o 3: 'D'
|
| o 2: 'C' 2
| |
| o 1: 'B' 1
|/
o 0: 'A'
$ hg rebase -s 5 -d 4
saved backup bundle to $TESTTMP/e/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 4: 'E'
|
o 3: 'D'
|
| o 2: 'C' 2
| |
| o 1: 'B' 1
|/
o 0: 'A'
$ hg export tip
# HG changeset patch
# User user1
# Date 0 0
# Node ID f338eb3c2c7cc5b5915676a2376ba7ac558c5213
# Parent 41acb9dca9eb976e84cd21fcb756b4afa5a35c09
E
diff -r 41acb9dca9eb -r f338eb3c2c7c z
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/z Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,2 @@
+d
+blah
$ 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)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up -q tip
$ hg tglog
@ 3: 'move2'
|
o 2: 'move1'
|
| o 1: 'change'
|/
o 0: 'add'
$ hg rebase --collapse -d 1
merging a and d to d
merging b and e to e
merging c and f to f
merging e and g to g
merging f and c to c
saved backup bundle to $TESTTMP/copies/.hg/strip-backup/*-backup.hg (glob)
$ hg st
$ hg st --copies --change .
A d
a
A g
b
R b
$ 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: 'Collapsed revision
| * move1
| * move2'
o 1: 'change'
|
o 0: 'add'
$ hg rebase --collapse -r 1 -d 0
abort: can't remove original changesets with unrebased descendants
(use --keep to keep original changesets)
[255]
Test collapsing in place
$ hg rebase --collapse -b . -d 0
saved backup bundle to $TESTTMP/copies/.hg/strip-backup/1352765a01d4-backup.hg
$ hg st --change . --copies
M a
M c
A d
a
A g
b
R b
$ cat a
a
a
$ cat c
c
c
$ cat d
a
a
$ cat g
b
b
$ cd ..