view tests/test-histedit-fold-non-commute.t @ 17103:5146de7bce96

convert: keep branch switching merges with ancestors (issue3340)

When running convert with a filemap, merge parents which are ancestors
of other parents are ignored. This is hardly a problem when parents
belong to the same branch, but the result could be confusing when named
branches are involved. With:

  -o-a1-a2-a3...     <- A
    \           \
     b1-b2-b3...-m-  <- B

If all b* revisions are discarded, it is useful to preserve 'm' even if
it is empty after filtering to record the branch switch.

This patch makes filemap preserve "ancestor parents" if there is no
"non-ancestor parent" on the same branch than the merge revision.

Remarks:
- I am not completely convinced by the reasons given above and those
  detailed by Matt in this thread:

http://selenic.com/pipermail/mercurial-devel/2012-May/040627.html

  The properties we try to preserve are not clearly defined. That said,
  I know this patch already helped someone on IRC and the tests output
  look reasonable.

- This is a new version of the original "convert: filemap must preserve
  fast-forward merges" patch. It has exactly the same output for 2
  parents merges, the additional complexity is here to handle more than
  two parents.

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

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

  $ EDITED="$TESTTMP/editedhistory"
  $ cat > $EDITED <<EOF
  > pick 177f92b77385 c
  > pick 055a42cdd887 d
  > fold bfa474341cc9 does not commute with e
  > pick e860deea161a e
  > pick 652413bf663e f
  > EOF
  $ initrepo ()
  > {
  >     hg init $1
  >     cd $1
  >     for x in a b c d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     echo a >> e
  >     hg ci -m 'does not commute with e'
  >     cd ..
  > }

  $ initrepo r
  $ cd r

log before edit
  $ hg log --graph
  @  changeset:   6:bfa474341cc9
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   5:652413bf663e
  |  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
  $ HGEDITOR="cat \"$EDITED\" > " hg histedit 177f92b77385 2>&1 | fixbundle
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  1 out of 1 hunks FAILED -- saving rejects to file e.rej
  abort: Fix up the change and run hg histedit --continue

fix up
  $ echo a > e
  $ hg add e
  $ cat > cat.py <<EOF
  > import sys
  > print open(sys.argv[1]).read()
  > print
  > print
  > EOF
  $ HGEDITOR="python cat.py" hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  d
  ***
  does not commute with e
  
  
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  file e already exists
  1 out of 1 hunks FAILED -- saving rejects to file e.rej
  abort: Fix up the change and run hg histedit --continue

just continue this time
  $ 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

log after edit
  $ hg log --graph
  @  changeset:   4:f768fd60ca34
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   3:671efe372e33
  |  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
  

contents of e
  $ hg cat e
  a

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

  $ cd ..