view tests/test-rebase-parameters.t @ 23702:c48924787eaa

filectx.parents: enforce changeid of parent to be in own changectx ancestors

Because of the way filenodes are computed, you can have multiple changesets
"introducing" the same file revision. For example, in the changeset graph
below, changeset 2 and 3 both change a file -to- and -from- the same content.

  o 3: content = new
  |
  | o 2: content = new
  |/
  o 1: content = old

In such cases, the file revision is create once, when 2 is added, and just reused
for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing
to it).  We'll call this situation "linkrev-shadowing". As the linkrev is used for
optimization purposes when walking a file history, the linkrev-shadowing
results in an unexpected jump to another branch during such a walk.. This leads to
multiple bugs with log, annotate and rename detection.

One element to fix such bugs is to ensure that walking the file history sticks on
the same topology as the changeset's history. For this purpose, we extend the
logic in 'basefilectx.parents' so that it always defines the proper changeset
to associate the parent file revision with. This "proper" changeset has to be an
ancestor of the changeset associated with the child file revision.

This logic is performed in the '_adjustlinkrev' function. This function is
given the starting changeset and all the information regarding the parent file
revision. If the linkrev for the file revision is an ancestor of the starting
changeset, the linkrev is valid and will be used. If it is not, we detected a
topological jump caused by linkrev shadowing, we are going to walk the
ancestors of the starting changeset until we find one setting the file to the
revision we are trying to create.

The performance impact appears acceptable:

- We are walking the changelog once for each filelog traversal (as there should
  be no overlap between searches),

- changelog traversal itself is fairly cheap, compared to what is likely going
  to be perform on the result on the filelog traversal,

- We only touch the manifest for ancestors touching the file, And such
  changesets are likely to be the one introducing the file. (except in
  pathological cases involving merge),

- We use manifest diff instead of full manifest unpacking to check manifest
  content, so it does not involve applying multiple diffs in most case.

- linkrev shadowing is not the common case.

Tests for fixed issues in log, annotate and rename detection have been
added.

But this changeset does not solve all problems. It fixes -ancestry-
computation, but if the linkrev-shadowed changesets is the starting one, we'll
still get things wrong. We'll have to fix the bootstrapping of such operations
in a later changeset. Also, the usage of `hg log FILE`  without --follow still
has issues with linkrev pointing to hidden changesets, because it relies on the
`filelog` revset which implement its own traversal logic that is still to be
fixed.

Thanks goes to:
- Matt Mackall: for nudging me in the right direction
- Julien Cristau and Rémi Cardona: for keep telling me linkrev bug were an
  evolution show stopper for 3 years.
- Durham Goode: for finding a new linkrev issue every few weeks
- Mads Kiilerich: for that last rename bug who raise this topic over my
  anoyance limit.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: '{desc}' {branches}\n"
  > EOF


  $ 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

  $ echo I > I
  $ hg ci -AmI
  adding I

  $ 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 ..


These fail:

  $ hg clone -q -u . a a1
  $ cd a1

  $ hg rebase -s 8 -d 7
  nothing to rebase
  [1]

  $ hg rebase --continue --abort
  abort: cannot use both abort and continue
  [255]

  $ hg rebase --continue --collapse
  abort: cannot use collapse with continue or abort
  [255]

  $ hg rebase --continue --dest 4
  abort: abort and continue do not allow specifying revisions
  [255]

  $ hg rebase --base 5 --source 4
  abort: cannot specify both a source and a base
  [255]

  $ hg rebase --rev 5 --source 4
  abort: cannot specify both a revision and a source
  [255]
  $ hg rebase --base 5 --rev 4
  abort: cannot specify both a revision and a base
  [255]

  $ hg rebase --rev '1 & !1'
  empty "rev" revision set - nothing to rebase
  [1]

  $ hg rebase --source '1 & !1'
  empty "source" revision set - nothing to rebase
  [1]

  $ hg rebase --base '1 & !1'
  empty "base" revision set - can't compute rebase set
  [1]

  $ hg rebase
  nothing to rebase - working directory parent is also destination
  [1]

  $ hg rebase -b.
  nothing to rebase - e7ec4e813ba6 is both "base" and destination
  [1]

  $ hg up -q 7

  $ hg rebase --traceback
  nothing to rebase - working directory parent is already an ancestor of destination e7ec4e813ba6
  [1]

  $ hg rebase -b.
  nothing to rebase - "base" 02de42196ebe is already an ancestor of destination e7ec4e813ba6
  [1]

  $ hg rebase --dest '1 & !1'
  abort: empty revision set
  [255]

These work:

Rebase with no arguments (from 3 onto 8):

  $ hg up -q -C 3

  $ hg rebase
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/42ccdea3bb16-backup.hg (glob)

  $ hg tglog
  @  8: 'D'
  |
  o  7: 'C'
  |
  o  6: 'B'
  |
  o  5: 'I'
  |
  o  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
Try to rollback after a rebase (fail):

  $ hg rollback
  no rollback information available
  [1]

  $ cd ..

Rebase with base == '.' => same as no arguments (from 3 onto 8):

  $ hg clone -q -u 3 a a2
  $ cd a2

  $ hg rebase --base .
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a2/.hg/strip-backup/42ccdea3bb16-backup.hg (glob)

  $ hg tglog
  @  8: 'D'
  |
  o  7: 'C'
  |
  o  6: 'B'
  |
  o  5: 'I'
  |
  o  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase with dest == branch(.) => same as no arguments (from 3 onto 8):

  $ hg clone -q -u 3 a a3
  $ cd a3

  $ hg rebase --dest 'branch(.)'
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a3/.hg/strip-backup/42ccdea3bb16-backup.hg (glob)

  $ hg tglog
  @  8: 'D'
  |
  o  7: 'C'
  |
  o  6: 'B'
  |
  o  5: 'I'
  |
  o  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
  $ cd ..


Specify only source (from 2 onto 8):

  $ hg clone -q -u . a a4
  $ cd a4

  $ hg rebase --source 'desc("C")'
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a4/.hg/strip-backup/5fddd98957c8-backup.hg (glob)

  $ hg tglog
  o  8: 'D'
  |
  o  7: 'C'
  |
  @  6: 'I'
  |
  o  5: 'H'
  |
  | o  4: 'G'
  |/|
  o |  3: 'F'
  | |
  | o  2: 'E'
  |/
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Specify only dest (from 3 onto 6):

  $ hg clone -q -u 3 a a5
  $ cd a5

  $ hg rebase --dest 6
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a5/.hg/strip-backup/42ccdea3bb16-backup.hg (glob)

  $ hg tglog
  @  8: 'D'
  |
  o  7: 'C'
  |
  o  6: 'B'
  |
  | o  5: 'I'
  | |
  | o  4: 'H'
  | |
  o |  3: 'G'
  |\|
  | o  2: 'F'
  | |
  o |  1: 'E'
  |/
  o  0: 'A'
  
  $ cd ..


Specify only base (from 1 onto 8):

  $ hg clone -q -u . a a6
  $ cd a6

  $ hg rebase --base 'desc("D")'
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a6/.hg/strip-backup/42ccdea3bb16-backup.hg (glob)

  $ hg tglog
  o  8: 'D'
  |
  o  7: 'C'
  |
  o  6: 'B'
  |
  @  5: 'I'
  |
  o  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
  $ cd ..


Specify source and dest (from 2 onto 7):

  $ hg clone -q -u . a a7
  $ cd a7

  $ hg rebase --source 2 --dest 7
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a7/.hg/strip-backup/5fddd98957c8-backup.hg (glob)

  $ hg tglog
  o  8: 'D'
  |
  o  7: 'C'
  |
  | @  6: 'I'
  |/
  o  5: 'H'
  |
  | o  4: 'G'
  |/|
  o |  3: 'F'
  | |
  | o  2: 'E'
  |/
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Specify base and dest (from 1 onto 7):

  $ hg clone -q -u . a a8
  $ cd a8

  $ hg rebase --base 3 --dest 7
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a8/.hg/strip-backup/42ccdea3bb16-backup.hg (glob)

  $ hg tglog
  o  8: 'D'
  |
  o  7: 'C'
  |
  o  6: 'B'
  |
  | @  5: 'I'
  |/
  o  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
  $ cd ..


Specify only revs (from 2 onto 8)

  $ hg clone -q -u . a a9
  $ cd a9

  $ hg rebase --rev 'desc("C")::'
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a9/.hg/strip-backup/5fddd98957c8-backup.hg (glob)

  $ hg tglog
  o  8: 'D'
  |
  o  7: 'C'
  |
  @  6: 'I'
  |
  o  5: 'H'
  |
  | o  4: 'G'
  |/|
  o |  3: 'F'
  | |
  | o  2: 'E'
  |/
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..

Test --tool parameter:

  $ hg init b
  $ cd b

  $ echo c1 > c1
  $ hg ci -Am c1
  adding c1

  $ echo c2 > c2
  $ hg ci -Am c2
  adding c2

  $ hg up -q 0
  $ echo c2b > c2
  $ hg ci -Am c2b
  adding c2
  created new head

  $ cd ..

  $ hg clone -q -u . b b1
  $ cd b1

  $ hg rebase -s 2 -d 1 --tool internal:local
  rebasing 2:e4e3f3546619 "c2b" (tip)
  note: rebase of 2:e4e3f3546619 created no changes to commit
  saved backup bundle to $TESTTMP/b1/.hg/strip-backup/e4e3f3546619-backup.hg (glob)

  $ hg cat c2
  c2

  $ cd ..


  $ hg clone -q -u . b b2
  $ cd b2

  $ hg rebase -s 2 -d 1 --tool internal:other
  rebasing 2:e4e3f3546619 "c2b" (tip)
  saved backup bundle to $TESTTMP/b2/.hg/strip-backup/e4e3f3546619-backup.hg (glob)

  $ hg cat c2
  c2b

  $ cd ..


  $ hg clone -q -u . b b3
  $ cd b3

  $ hg rebase -s 2 -d 1 --tool internal:fail
  rebasing 2:e4e3f3546619 "c2b" (tip)
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ hg summary
  parent: 1:56daeba07f4b 
   c2
  parent: 2:e4e3f3546619 tip
   c2b
  branch: default
  commit: 1 modified, 1 unresolved (merge)
  update: (current)
  rebase: 0 rebased, 1 remaining (rebase --continue)

  $ hg resolve -l
  U c2

  $ hg resolve -m c2
  (no more unresolved files)
  $ hg rebase -c --tool internal:fail
  tool option will be ignored
  rebasing 2:e4e3f3546619 "c2b" (tip)
  note: rebase of 2:e4e3f3546619 created no changes to commit
  saved backup bundle to $TESTTMP/b3/.hg/strip-backup/e4e3f3546619-backup.hg (glob)

  $ hg rebase -i
  abort: interactive history editing is supported by the 'histedit' extension (see 'hg help histedit')
  [255]

  $ hg rebase --interactive
  abort: interactive history editing is supported by the 'histedit' extension (see 'hg help histedit')
  [255]

  $ cd ..

No common ancestor

  $ hg init separaterepo
  $ cd separaterepo
  $ touch a
  $ hg commit -Aqm a
  $ hg up -q null
  $ touch b
  $ hg commit -Aqm b
  $ hg rebase -d 0
  nothing to rebase from d7486e00c6f1 to 3903775176ed
  [1]
  $ cd ..