tests/test-rebase-obsolete.t

revlog: change generaldelta delta parent heuristic

The old generaldelta heuristic was "if p1 (or p2) was closer than the last full text,
use it, otherwise use prev". This was problematic when a repo contained multiple
branches that were very different. If commits to branch A were pushed, and the
last full text was branch B, it would generate a fulltext. Then if branch B was
pushed, it would generate another fulltext. The problem is that the last
fulltext (and delta'ing against `prev` in general) has no correlation with the
contents of the incoming revision, and therefore will always have degenerate
cases.

According to the blame, that algorithm was chosen to minimize the chain length.
Since there is already code that protects against that (the delta-vs-fulltext
code), and since it has been improved since the original generaldelta algorithm
went in (2011), I believe the chain length criteria will still be preserved.

The new algorithm always diffs against p1 (or p2 if it's closer), unless the
resulting delta will fail the delta-vs-fulltext check, in which case we delta
against prev.

Some before and after stats on manifest.d size.

internal large repo
old heuristic - 2.0 GB
new heuristic - 1.2 GB

mozilla-central
old heuristic - 242 MB
new heuristic - 261 MB

The regression in mozilla central is due to the new heuristic choosing p2r as
the delta when it's closer to the tip. Switching the algorithm to always prefer
p1r brings the size back down (242 MB). This is result of the way in which
mozilla does merges and pushes, and the result could easily swing the other
direction in other repos (depending on if they merge X into Y or Y into X), but
will never be as degenerate as before.

I future patch will address the regression by introducing an optional, even more
aggressive delta heuristic which will knock the mozilla manifest size down
dramatically.

==========================
Test rebase with obsolete
==========================

Enable obsolete

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} {desc|firstline}
  > [experimental]
  > evolution=createmarkers,allowunstable
  > [phases]
  > publish=False
  > [extensions]'
  > rebase=
  > EOF

Setup rebase canonical repo

  $ hg init base
  $ cd base
  $ 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 log -G
  @  7:02de42196ebe H
  |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  | o  3:32af7686d403 D
  | |
  | o  2:5fddd98957c8 C
  | |
  | o  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ cd ..

simple rebase
---------------------------------

  $ hg clone base simple
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd simple
  $ hg up 32af7686d403
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg rebase -d eea13746799a
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  $ hg log -G
  @  10:8eeb3c33ad33 D
  |
  o  9:2327fea05063 C
  |
  o  8:e4e5be0395b2 B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  @  10:8eeb3c33ad33 D
  |
  o  9:2327fea05063 C
  |
  o  8:e4e5be0395b2 B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 e4e5be0395b2cbd471ed22a26b1b6a1a0658a794 0 (*) {'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 2327fea05063f39961b14cb69435a9898dc9a245 0 (*) {'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 8eeb3c33ad33d452c89e5dcf611c347f978fb42b 0 (*) {'user': 'test'} (glob)


  $ cd ..

empty changeset
---------------------------------

  $ hg clone base empty
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd empty
  $ hg up eea13746799a
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

We make a copy of both the first changeset in the rebased and some other in the
set.

  $ hg graft 42ccdea3bb16 32af7686d403
  grafting 1:42ccdea3bb16 "B"
  grafting 3:32af7686d403 "D"
  $ hg rebase  -s 42ccdea3bb16 -d .
  rebasing 1:42ccdea3bb16 "B"
  note: rebase of 1:42ccdea3bb16 created no changes to commit
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  note: rebase of 3:32af7686d403 created no changes to commit
  $ hg log -G
  o  10:5ae4c968c6ac C
  |
  @  9:08483444fef9 D
  |
  o  8:8877864f1edb B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  o  10:5ae4c968c6ac C
  |
  @  9:08483444fef9 D
  |
  o  8:8877864f1edb B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 0 {cd010b8cd998f3981a5a8115f94f8da4ab506089} (*) {'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 5ae4c968c6aca831df823664e706c9d4aa34473d 0 (*) {'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 0 {5fddd98957c8a54a4d436dfe1da9d87f21a1b97b} (*) {'user': 'test'} (glob)


More complex case were part of the rebase set were already rebased

  $ hg rebase --rev 'desc(D)' --dest 'desc(H)'
  rebasing 9:08483444fef9 "D"
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 0 {cd010b8cd998f3981a5a8115f94f8da4ab506089} (*) {'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 5ae4c968c6aca831df823664e706c9d4aa34473d 0 (*) {'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 0 {5fddd98957c8a54a4d436dfe1da9d87f21a1b97b} (*) {'user': 'test'} (glob)
  08483444fef91d6224f6655ee586a65d263ad34c 4596109a6a4328c398bde3a4a3b6737cfade3003 0 (*) {'user': 'test'} (glob)
  $ hg log -G
  @  11:4596109a6a43 D
  |
  | o  10:5ae4c968c6ac C
  | |
  | x  9:08483444fef9 D
  | |
  | o  8:8877864f1edb B
  | |
  o |  7:02de42196ebe H
  | |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg rebase --source 'desc(B)' --dest 'tip'
  rebasing 8:8877864f1edb "B"
  rebasing 9:08483444fef9 "D"
  note: rebase of 9:08483444fef9 created no changes to commit
  rebasing 10:5ae4c968c6ac "C"
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 0 {cd010b8cd998f3981a5a8115f94f8da4ab506089} (*) {'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 5ae4c968c6aca831df823664e706c9d4aa34473d 0 (*) {'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 0 {5fddd98957c8a54a4d436dfe1da9d87f21a1b97b} (*) {'user': 'test'} (glob)
  08483444fef91d6224f6655ee586a65d263ad34c 4596109a6a4328c398bde3a4a3b6737cfade3003 0 (*) {'user': 'test'} (glob)
  8877864f1edb05d0e07dc4ba77b67a80a7b86672 462a34d07e599b87ea08676a449373fe4e2e1347 0 (*) {'user': 'test'} (glob)
  08483444fef91d6224f6655ee586a65d263ad34c 0 {8877864f1edb05d0e07dc4ba77b67a80a7b86672} (*) {'user': 'test'} (glob)
  5ae4c968c6aca831df823664e706c9d4aa34473d 98f6af4ee9539e14da4465128f894c274900b6e5 0 (*) {'user': 'test'} (glob)
  $ hg log --rev 'divergent()'
  $ hg log -G
  o  13:98f6af4ee953 C
  |
  o  12:462a34d07e59 B
  |
  @  11:4596109a6a43 D
  |
  o  7:02de42196ebe H
  |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --style default --debug -r 4596109a6a4328c398bde3a4a3b6737cfade3003
  changeset:   11:4596109a6a4328c398bde3a4a3b6737cfade3003
  phase:       draft
  parent:      7:02de42196ebee42ef284b6780a87cdc96e8eaab6
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    11:a91006e3a02f1edf631f7018e6e5684cf27dd905
  user:        Nicolas Dumazet <[e-mail]>
  date:        Sat Apr 30 15:24:48 2011 +0200
  files+:      D
  extra:       branch=default
  extra:       rebase_source=08483444fef91d6224f6655ee586a65d263ad34c
  extra:       source=32af7686d403cf45b5d95f2d70cebea587ac806a
  description:
  D
  
  
  $ cd ..

collapse rebase
---------------------------------

  $ hg clone base collapse
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd collapse
  $ hg rebase  -s 42ccdea3bb16 -d eea13746799a --collapse
  rebasing 1:42ccdea3bb16 "B"
  note: rebase of 1:42ccdea3bb16 created no changes to commit
  rebasing 2:5fddd98957c8 "C"
  note: rebase of 2:5fddd98957c8 created no changes to commit
  rebasing 3:32af7686d403 "D"
  note: rebase of 3:32af7686d403 created no changes to commit
  $ hg log -G
  o  8:4dc2197e807b Collapsed revision
  |
  | @  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  o  8:4dc2197e807b Collapsed revision
  |
  | @  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg id --debug -r tip
  4dc2197e807bae9817f09905b50ab288be2dbbcf tip
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 4dc2197e807bae9817f09905b50ab288be2dbbcf 0 (*) {'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 4dc2197e807bae9817f09905b50ab288be2dbbcf 0 (*) {'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 4dc2197e807bae9817f09905b50ab288be2dbbcf 0 (*) {'user': 'test'} (glob)

  $ cd ..

Rebase set has hidden descendants
---------------------------------

We rebase a changeset which has a hidden changeset. The hidden changeset must
not be rebased.

  $ hg clone base hidden
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd hidden
  $ hg rebase -s 5fddd98957c8 -d eea13746799a
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  $ hg rebase -s 42ccdea3bb16 -d 02de42196ebe
  rebasing 1:42ccdea3bb16 "B"
  $ hg log -G
  o  10:7c6027df6a99 B
  |
  | o  9:cf44d2f5a9f4 D
  | |
  | o  8:e273c5e7d2d2 C
  | |
  @ |  7:02de42196ebe H
  | |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  o  10:7c6027df6a99 B
  |
  | o  9:cf44d2f5a9f4 D
  | |
  | o  8:e273c5e7d2d2 C
  | |
  @ |  7:02de42196ebe H
  | |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg debugobsolete
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b e273c5e7d2d29df783dce9f9eaa3ac4adc69c15d 0 (*) {'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a cf44d2f5a9f4297a62be94cbdd3dff7c7dc54258 0 (*) {'user': 'test'} (glob)
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 7c6027df6a99d93f461868e5433f63bde20b6dfb 0 (*) {'user': 'test'} (glob)

Test that rewriting leaving instability behind is allowed
---------------------------------------------------------------------

  $ hg log -r 'children(8)'
  9:cf44d2f5a9f4 D (no-eol)
  $ hg rebase -r 8
  rebasing 8:e273c5e7d2d2 "C"
  $ hg log -G
  o  11:0d8f238b634c C
  |
  o  10:7c6027df6a99 B
  |
  | o  9:cf44d2f5a9f4 D
  | |
  | x  8:e273c5e7d2d2 C
  | |
  @ |  7:02de42196ebe H
  | |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  


Test multiple root handling
------------------------------------

  $ hg rebase --dest 4 --rev '7+11+9'
  rebasing 7:02de42196ebe "H"
  rebasing 9:cf44d2f5a9f4 "D"
  not rebasing ignored 10:7c6027df6a99 "B"
  rebasing 11:0d8f238b634c "C" (tip)
  $ hg log -G
  o  14:1e8370e38cca C
  |
  | o  13:102b4c1d889b D
  | |
  @ |  12:bfe264faf697 H
  |/
  | o  10:7c6027df6a99 B
  | |
  | x  7:02de42196ebe H
  | |
  +---o  6:eea13746799a G
  | |/
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ cd ..

test on rebase dropping a merge

(setup)

  $ hg init dropmerge
  $ cd dropmerge
  $ 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 3
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 7
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'M'
  $ echo I > I
  $ hg add I
  $ hg ci -m I
  $ hg log -G
  @  9:4bde274eefcf I
  |
  o    8:53a6a128b2b7 M
  |\
  | o  7:02de42196ebe H
  | |
  | | o  6:eea13746799a G
  | |/|
  | o |  5:24b6387c8c8c F
  | | |
  | | o  4:9520eea781bc E
  | |/
  o |  3:32af7686d403 D
  | |
  o |  2:5fddd98957c8 C
  | |
  o |  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
(actual test)

  $ hg rebase --dest 6 --rev '((desc(H) + desc(D))::) - desc(M)'
  rebasing 3:32af7686d403 "D"
  rebasing 7:02de42196ebe "H"
  not rebasing ignored 8:53a6a128b2b7 "M"
  rebasing 9:4bde274eefcf "I" (tip)
  $ hg log -G
  @  12:acd174b7ab39 I
  |
  o  11:6c11a6218c97 H
  |
  | o  10:b5313c85b22e D
  |/
  | o    8:53a6a128b2b7 M
  | |\
  | | x  7:02de42196ebe H
  | | |
  o---+  6:eea13746799a G
  | | |
  | | o  5:24b6387c8c8c F
  | | |
  o---+  4:9520eea781bc E
   / /
  x |  3:32af7686d403 D
  | |
  o |  2:5fddd98957c8 C
  | |
  o |  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  

Test hidden changesets in the rebase set (issue4504)

  $ hg up --hidden 9
  3 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo J > J
  $ hg add J
  $ hg commit -m J
  $ hg debugobsolete `hg log --rev . -T '{node}'`

  $ hg rebase --rev .~1::. --dest 'max(desc(D))' --traceback
  rebasing 9:4bde274eefcf "I"
  rebasing 13:06edfc82198f "J" (tip)
  $ hg log -G
  @  15:5ae8a643467b J
  |
  o  14:9ad579b4a5de I
  |
  | o  12:acd174b7ab39 I
  | |
  | o  11:6c11a6218c97 H
  | |
  o |  10:b5313c85b22e D
  |/
  | o    8:53a6a128b2b7 M
  | |\
  | | x  7:02de42196ebe H
  | | |
  o---+  6:eea13746799a G
  | | |
  | | o  5:24b6387c8c8c F
  | | |
  o---+  4:9520eea781bc E
   / /
  x |  3:32af7686d403 D
  | |
  o |  2:5fddd98957c8 C
  | |
  o |  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A