tests/test-rebase-rename.t
author Arun Kulshreshtha <akulshreshtha@janestreet.com>
Tue, 30 Aug 2022 15:29:55 -0400
changeset 49491 c6a1beba27e9
parent 45792 1703a7f9d5b8
permissions -rw-r--r--
bisect: avoid copying ancestor list for non-merge commits During a bisection, hg needs to compute a list of all ancestors for every candidate commit. This is accomplished via a bottom-up traversal of the set of candidates, during which each revision's ancestor list is populated using the ancestor list of its parent(s). Previously, this involved copying the entire list, which could be very long in if the bisection range was large. To help improve this, we can observe that each candidate commit is visited exactly once, at which point its ancestor list is copied into its children's lists and then dropped. In the case of non-merge commits, a commit's ancestor list consists exactly of its parent's list plus itself. This means that we can trivially reuse the parent's existing list for one of its non-merge children, which avoids copying entirely if that commit is the parent's only child. This makes bisections over linear ranges of commits much faster. During some informal testing in the large publicly-available `mozilla-central` repository, this noticeably sped up bisections over large ranges of history: Setup: $ cd mozilla-central $ hg bisect --reset $ hg bisect --good 0 $ hg log -r tip -T '{rev}\n' 628417 Test: $ time hg bisect --bad tip --noupdate Before: real 3m35.927s user 3m35.553s sys 0m0.319s After: real 1m41.142s user 1m40.810s sys 0m0.285s

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [alias]
  > tlog  = log --template "{rev}: {node|short} '{desc}' {branches}\n"
  > tglog = tlog --graph
  > EOF


  $ hg init a
  $ cd a

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

  $ echo b > d/b
  $ hg ci -Am B
  adding d/b

  $ hg mv d d-renamed
  moving d/b to d-renamed/b
  $ hg ci -m 'rename B'

  $ hg up -q -C 1

  $ hg mv a a-renamed
  $ echo x > d/x
  $ hg add d/x

  $ hg ci -m 'rename A'
  created new head

  $ hg tglog
  @  3: 73a3ee40125d 'rename A'
  |
  | o  2: 220d0626d185 'rename B'
  |/
  o  1: 3ab5da9a5c01 'B'
  |
  o  0: 1994f17a630e 'A'
  

Rename is tracked:

  $ hg tlog -p --git -r tip
  3: 73a3ee40125d 'rename A' 
  diff --git a/a b/a-renamed
  rename from a
  rename to a-renamed
  diff --git a/d/x b/d/x
  new file mode 100644
  --- /dev/null
  +++ b/d/x
  @@ -0,0 +1,1 @@
  +x
  
Rebase the revision containing the rename:

  $ hg rebase -s 3 -d 2
  rebasing 3:73a3ee40125d tip "rename A"
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/73a3ee40125d-1d78ebcf-rebase.hg

  $ hg tglog
  @  3: 032a9b75e83b 'rename A'
  |
  o  2: 220d0626d185 'rename B'
  |
  o  1: 3ab5da9a5c01 'B'
  |
  o  0: 1994f17a630e 'A'
  

Rename is not lost:

  $ hg tlog -p --git -r tip
  3: 032a9b75e83b 'rename A' 
  diff --git a/a b/a-renamed
  rename from a
  rename to a-renamed
  diff --git a/d-renamed/x b/d-renamed/x
  new file mode 100644
  --- /dev/null
  +++ b/d-renamed/x
  @@ -0,0 +1,1 @@
  +x
  

Rebased revision does not contain information about b (issue3739)

  $ hg log -r 3 --debug
  changeset:   3:032a9b75e83bff1dcfb6cbfa4ef50a704bf1b569
  tag:         tip
  phase:       draft
  parent:      2:220d0626d185f372d9d8f69d9c73b0811d7725f7
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    3:035d66b27a1b06b2d12b46d41a39adb7a200c370
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      a-renamed d-renamed/x
  files-:      a
  extra:       branch=default
  extra:       rebase_source=73a3ee40125d6f0f347082e5831ceccb3f005f8a
  description:
  rename A
  
  

  $ repeatchange() {
  >   hg checkout $1
  >   hg cp a z
  >   echo blah >> z
  >   hg commit -Am "$2" --user "$3"
  > }
  $ repeatchange 1 "E" "user1"
  2 files updated, 0 files merged, 3 files removed, 0 files unresolved
  created new head
  $ repeatchange 1 "E" "user2"
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  created new head
  $ hg tglog
  @  5: af8ad1f97097 'E'
  |
  | o  4: 60f545c27784 'E'
  |/
  | o  3: 032a9b75e83b 'rename A'
  | |
  | o  2: 220d0626d185 'rename B'
  |/
  o  1: 3ab5da9a5c01 'B'
  |
  o  0: 1994f17a630e 'A'
  
  $ hg rebase -s 5 -d 4
  rebasing 5:af8ad1f97097 tip "E"
  note: not rebasing 5:af8ad1f97097 tip "E", its destination already has all its changes
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/af8ad1f97097-c3e90708-rebase.hg
  $ hg tglog
  @  4: 60f545c27784 'E'
  |
  | o  3: 032a9b75e83b 'rename A'
  | |
  | o  2: 220d0626d185 'rename B'
  |/
  o  1: 3ab5da9a5c01 'B'
  |
  o  0: 1994f17a630e 'A'
  
  $ hg export tip
  # HG changeset patch
  # User user1
  # Date 0 0
  #      Thu Jan 01 00:00:00 1970 +0000
  # Node ID 60f545c277846e6bad309919bae3ae106f59cb39
  # Parent  3ab5da9a5c01faa02c20f2ec4870a4f689c92da6
  E
  
  diff -r 3ab5da9a5c01 -r 60f545c27784 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 @@
  +a
  +blah

  $ cd ..


  $ hg init b
  $ cd b

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

  $ echo b > b
  $ hg ci -Am B
  adding b

  $ hg cp b b-copied
  $ hg ci -Am 'copy B'

  $ hg up -q -C 1

  $ hg cp a a-copied
  $ hg ci -m 'copy A'
  created new head

  $ hg tglog
  @  3: 0a8162ff18a8 'copy A'
  |
  | o  2: 39e588434882 'copy B'
  |/
  o  1: 6c81ed0049f8 'B'
  |
  o  0: 1994f17a630e 'A'
  
Copy is tracked:

  $ hg tlog -p --git -r tip
  3: 0a8162ff18a8 'copy A' 
  diff --git a/a b/a-copied
  copy from a
  copy to a-copied
  
Rebase the revision containing the copy:

  $ hg rebase -s 3 -d 2
  rebasing 3:0a8162ff18a8 tip "copy A"
  saved backup bundle to $TESTTMP/b/.hg/strip-backup/0a8162ff18a8-dd06302a-rebase.hg

  $ hg tglog
  @  3: 98f6e6dbf45a 'copy A'
  |
  o  2: 39e588434882 'copy B'
  |
  o  1: 6c81ed0049f8 'B'
  |
  o  0: 1994f17a630e 'A'
  

Copy is not lost:

  $ hg tlog -p --git -r tip
  3: 98f6e6dbf45a 'copy A' 
  diff --git a/a b/a-copied
  copy from a
  copy to a-copied
  

Rebased revision does not contain information about b (issue3739)

  $ hg log -r 3 --debug
  changeset:   3:98f6e6dbf45ab54079c2237fbd11066a5c41a11d
  tag:         tip
  phase:       draft
  parent:      2:39e588434882ff77d01229d169cdc77f29e8855e
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    3:2232f329d66fffe3930d43479ae624f66322b04d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      a-copied
  extra:       branch=default
  extra:       rebase_source=0a8162ff18a8900df8df8ef7ac0046955205613e
  description:
  copy A
  
  

  $ cd ..


Test rebase across repeating renames:

  $ hg init repo

  $ cd repo

  $ echo testing > file1.txt
  $ hg add file1.txt
  $ hg ci -m "Adding file1"

  $ hg rename file1.txt file2.txt
  $ hg ci -m "Rename file1 to file2"

  $ echo Unrelated change > unrelated.txt
  $ hg add unrelated.txt
  $ hg ci -m "Unrelated change"

  $ hg rename file2.txt file1.txt
  $ hg ci -m "Rename file2 back to file1"

  $ hg update -r -2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo Another unrelated change >> unrelated.txt
  $ hg ci -m "Another unrelated change"
  created new head

  $ hg tglog
  @  4: b918d683b091 'Another unrelated change'
  |
  | o  3: 1ac17e43d8aa 'Rename file2 back to file1'
  |/
  o  2: 480101d66d8d 'Unrelated change'
  |
  o  1: be44c61debd2 'Rename file1 to file2'
  |
  o  0: 8ce9a346991d 'Adding file1'
  

  $ hg rebase -s 4 -d 3
  rebasing 4:b918d683b091 tip "Another unrelated change"
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/b918d683b091-3024bc57-rebase.hg

  $ hg diff --stat -c .
   unrelated.txt |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)

  $ cd ..

Verify that copies get preserved (issue4192).
  $ hg init copy-gets-preserved
  $ cd copy-gets-preserved

  $ echo a > a
  $ hg add a
  $ hg commit --message "File a created"
  $ hg copy a b
  $ echo b > b
  $ hg commit --message "File b created as copy of a and modified"
  $ hg copy b c
  $ echo c > c
  $ hg commit --message "File c created as copy of b and modified" ##
  $ hg copy c d
  $ echo d > d
  $ hg commit --message "File d created as copy of c and modified (child of 327f772bc074)"

Note that there are four entries in the log for d
  $ hg tglog --follow d
  @  3: 6be224292cfa 'File d created as copy of c and modified (child of 327f772bc074)'
  |
  o  2: 327f772bc074 'File c created as copy of b and modified'
  |
  o  1: 79d255d24ad2 'File b created as copy of a and modified'
  |
  o  0: b220cd6d2326 'File a created'
  
Update back to before we performed copies, and inject an unrelated change.
  $ hg update 0
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved

  $ echo unrelated > unrelated
  $ hg add unrelated
  $ hg commit --message "Unrelated file created"
  created new head
  $ hg update 4
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

Rebase the copies on top of the unrelated change.
  $ hg rebase --source 1 --dest 4
  rebasing 1:79d255d24ad2 "File b created as copy of a and modified"
  rebasing 2:327f772bc074 "File c created as copy of b and modified"
  rebasing 3:6be224292cfa "File d created as copy of c and modified (child of 327f772bc074)"
  saved backup bundle to $TESTTMP/copy-gets-preserved/.hg/strip-backup/79d255d24ad2-a3e674e3-rebase.hg
  $ hg update 4
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

There should still be four entries in the log for d
  $ hg tglog --follow d
  @  4: afbdde3a60d5 'File d created as copy of c and modified (child of af74b229bc02)'
  |
  o  3: af74b229bc02 'File c created as copy of b and modified'
  |
  o  2: 68bf06433839 'File b created as copy of a and modified'
  :
  o  0: b220cd6d2326 'File a created'
  
Same steps as above, but with --collapse on rebase to make sure the
copy records collapse correctly.
  $ hg co 1
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ echo more >> unrelated
  $ hg ci -m 'unrelated commit is unrelated'
  created new head
  $ hg rebase -s 2 --dest 5 --collapse
  rebasing 2:68bf06433839 "File b created as copy of a and modified"
  rebasing 3:af74b229bc02 "File c created as copy of b and modified"
  merging b and c to c
  rebasing 4:afbdde3a60d5 "File d created as copy of c and modified (child of af74b229bc02)"
  merging c and d to d
  saved backup bundle to $TESTTMP/copy-gets-preserved/.hg/strip-backup/68bf06433839-29d5057f-rebase.hg
  $ hg co tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

This should show both revision 3 and 0 since 'd' was transitively a
copy of 'a'.

  $ hg tglog --follow d
  @  3: 75708a266e56 'Collapsed revision
  :  * File b created as copy of a and modified
  :  * File c created as copy of b and modified
  :  * File d created as copy of c and modified (child of af74b229bc02)'
  o  0: b220cd6d2326 'File a created'
  
  $ hg log -G -Tcompact
  @  3[tip]   75708a266e56   1970-01-01 00:00 +0000   test
  |    Collapsed revision
  |
  o  2   15258cf0cf10   1970-01-01 00:00 +0000   test
  |    unrelated commit is unrelated
  |
  o  1   1d689898494b   1970-01-01 00:00 +0000   test
  |    Unrelated file created
  |
  o  0   b220cd6d2326   1970-01-01 00:00 +0000   test
       File a created
  

  $ cd ..