view tests/test-histedit-edit.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.

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ initrepo ()
  > {
  >     hg init r
  >     cd r
  >     for x in a b c d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  > }

  $ initrepo

log before edit
  $ hg log --graph
  @  changeset:   5:652413bf663e
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e860deea161a
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     e
  |
  o  changeset:   3:055a42cdd887
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

edit the history
  $ hg histedit 177f92b77385 --commands - 2>&1 << EOF| fixbundle
  > pick 177f92b77385 c
  > pick 055a42cdd887 d
  > edit e860deea161a e
  > pick 652413bf663e f
  > EOF
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  Make changes as needed, you may commit or record as needed now.
  When you are finished, run hg histedit --continue to resume.

Go at a random point and try to continue

  $ hg id -n
  3+
  $ hg up 0
  abort: histedit in progress
  (use 'hg histedit --continue' or 'hg histedit --abort')
  [255]

commit, then edit the revision
  $ hg ci -m 'wat'
  created new head
  $ echo a > e
  $ HGEDITOR='echo foobaz > ' hg histedit --continue 2>&1 | fixbundle
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg log --graph
  @  changeset:   6:b5f70786f9b0
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:a5e1ba2f7afb
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     foobaz
  |
  o  changeset:   4:1a60820cd1f6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     wat
  |
  o  changeset:   3:055a42cdd887
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

  $ hg cat e
  a

check histedit_source

  $ hg log --debug --rev 5
  changeset:   5:a5e1ba2f7afb899ef1581cea528fd885d2fca70d
  phase:       draft
  parent:      4:1a60820cd1f6004a362aa622ebc47d59bc48eb34
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    5:5ad3be8791f39117565557781f5464363b918a45
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       e
  extra:       branch=default
  extra:       histedit_source=e860deea161a2f77de56603b340ebbb4536308ae
  description:
  foobaz
  
  

  $ hg histedit tip --commands - 2>&1 <<EOF| fixbundle
  > edit b5f70786f9b0 f
  > EOF
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  Make changes as needed, you may commit or record as needed now.
  When you are finished, run hg histedit --continue to resume.
  $ hg status
  A f

  $ hg summary
  parent: 5:a5e1ba2f7afb 
   foobaz
  branch: default
  commit: 1 added (new branch head)
  update: 1 new changesets (update)
  hist:   1 remaining (histedit --continue)

(test also that editor is invoked if histedit is continued for
"edit" action)

  $ HGEDITOR='cat' hg histedit --continue
  f
  
  
  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 f
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/r/.hg/strip-backup/b5f70786f9b0-backup.hg (glob)

  $ hg status

log after edit
  $ hg log --limit 1
  changeset:   6:a107ee126658
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     f
  

say we'll change the message, but don't.
  $ cat > ../edit.sh <<EOF
  > cat "\$1" | sed s/pick/mess/ > tmp
  > mv tmp "\$1"
  > EOF
  $ HGEDITOR="sh ../edit.sh" hg histedit tip 2>&1 | fixbundle
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status
  $ hg log --limit 1
  changeset:   6:1fd3b2fe7754
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     f
  

modify the message

check saving last-message.txt, at first

  $ cat > $TESTTMP/commitfailure.py <<EOF
  > from mercurial import util
  > def reposetup(ui, repo):
  >     class commitfailure(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             raise util.Abort('emulating unexpected abort')
  >     repo.__class__ = commitfailure
  > EOF
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > # this failure occurs before editor invocation
  > commitfailure = $TESTTMP/commitfailure.py
  > EOF

  $ cat > $TESTTMP/editor.sh <<EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > echo "check saving last-message.txt" >> \$1
  > EOF

(test that editor is not invoked before transaction starting)

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg histedit tip --commands - 2>&1 << EOF | fixbundle
  > mess 1fd3b2fe7754 f
  > EOF
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  abort: emulating unexpected abort
  $ test -f .hg/last-message.txt
  [1]

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > commitfailure = !
  > EOF
  $ hg histedit --abort -q

(test that editor is invoked and commit message is saved into
"last-message.txt")

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > # this failure occurs after editor invocation
  > pretxncommit.unexpectedabort = false
  > EOF

  $ hg status --rev '1fd3b2fe7754^1' --rev 1fd3b2fe7754
  A f

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg histedit tip --commands - 2>&1 << EOF
  > mess 1fd3b2fe7754 f
  > EOF
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  adding f
  ==== before editing
  f
  
  
  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 f
  ====
  transaction abort!
  rollback completed
  note: commit message saved in .hg/last-message.txt
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]
  $ cat .hg/last-message.txt
  f
  
  
  check saving last-message.txt

(test also that editor is invoked if histedit is continued for "message"
action)

  $ HGEDITOR=cat hg histedit --continue
  f
  
  
  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 f
  transaction abort!
  rollback completed
  note: commit message saved in .hg/last-message.txt
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > pretxncommit.unexpectedabort =
  > EOF
  $ hg histedit --abort -q

then, check "modify the message" itself

  $ hg histedit tip --commands - 2>&1 << EOF | fixbundle
  > mess 1fd3b2fe7754 f
  > EOF
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status
  $ hg log --limit 1
  changeset:   6:62feedb1200e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     f
  

rollback should not work after a histedit
  $ hg rollback
  no rollback information available
  [1]

  $ cd ..
  $ hg clone -qr0 r r0
  $ cd r0
  $ hg phase -fdr0
  $ hg histedit --commands - 0 2>&1 << EOF
  > edit cb9a9f314b8b a > $EDITED
  > EOF
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  adding a
  Make changes as needed, you may commit or record as needed now.
  When you are finished, run hg histedit --continue to resume.
  [1]
  $ HGEDITOR=true hg histedit --continue
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/r0/.hg/strip-backup/cb9a9f314b8b-backup.hg (glob)