view tests/test-filebranch.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.

This test makes sure that we don't mark a file as merged with its ancestor
when we do a merge.

  $ cat <<EOF > merge
  > import sys, os
  > print "merging for", os.path.basename(sys.argv[1])
  > EOF
  $ HGMERGE="python ../merge"; export HGMERGE

Creating base:

  $ hg init a
  $ cd a
  $ echo 1 > foo
  $ echo 1 > bar
  $ echo 1 > baz
  $ echo 1 > quux
  $ hg add foo bar baz quux
  $ hg commit -m "base"

  $ cd ..
  $ hg clone a b
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved

Creating branch a:

  $ cd a
  $ echo 2a > foo
  $ echo 2a > bar
  $ hg commit -m "branch a"

Creating branch b:

  $ cd ..
  $ cd b
  $ echo 2b > foo
  $ echo 2b > baz
  $ hg commit -m "branch b"

We shouldn't have anything but n state here:

  $ hg debugstate --nodates | grep -v "^n"
  [1]

Merging:

  $ hg pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg merge -v
  resolving manifests
  getting bar
  merging foo
  merging for foo
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo 2m > foo
  $ echo 2b > baz
  $ echo new > quux

We shouldn't have anything but foo in merge state here:

  $ hg debugstate --nodates | grep "^m"
  m 644          3 foo

  $ hg ci -m "merge"

main: we should have a merge here:

  $ hg debugindex --changelog
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0      73      0       0 cdca01651b96 000000000000 000000000000
       1        73      68      1       1 f6718a9cb7f3 cdca01651b96 000000000000
       2       141      68      2       2 bdd988058d16 cdca01651b96 000000000000
       3       209      66      3       3 d8a521142a3c f6718a9cb7f3 bdd988058d16

log should show foo and quux changed:

  $ hg log -v -r tip
  changeset:   3:d8a521142a3c
  tag:         tip
  parent:      1:f6718a9cb7f3
  parent:      2:bdd988058d16
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       foo quux
  description:
  merge
  
  

foo: we should have a merge here:

  $ hg debugindex foo
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0       3      0       0 b8e02f643373 000000000000 000000000000
       1         3       4      1       1 2ffeddde1b65 b8e02f643373 000000000000
       2         7       4      2       2 33d1fb69067a b8e02f643373 000000000000
       3        11       4      3       3 aa27919ee430 2ffeddde1b65 33d1fb69067a

bar: we should not have a merge here:

  $ hg debugindex bar
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0       3      0       0 b8e02f643373 000000000000 000000000000
       1         3       4      1       2 33d1fb69067a b8e02f643373 000000000000

baz: we should not have a merge here:

  $ hg debugindex baz
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0       3      0       0 b8e02f643373 000000000000 000000000000
       1         3       4      1       1 2ffeddde1b65 b8e02f643373 000000000000

quux: we should not have a merge here:

  $ hg debugindex quux
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0       3      0       0 b8e02f643373 000000000000 000000000000
       1         3       5      1       3 6128c0f33108 b8e02f643373 000000000000

Manifest entries should match tips of all files:

  $ hg manifest --debug
  33d1fb69067a0139622a3fa3b7ba1cdb1367972e 644   bar
  2ffeddde1b65b4827f6746174a145474129fa2ce 644   baz
  aa27919ee4303cfd575e1fb932dd64d75aa08be4 644   foo
  6128c0f33108e8cfbb4e0824d13ae48b466d7280 644   quux

Everything should be clean now:

  $ hg status

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  4 files, 4 changesets, 10 total revisions

  $ cd ..