view tests/test-newbranch.t @ 13158:9e7e24052745

merge: fast-forward merge with descendant

issue2538 gives a case where a changeset is merged with its child (which is on
another branch), and to my surprise the result is a real merge with two
parents, not just a "fast forward" "merge" with only the child as parent.

That is essentially the same as issue619.

Is the existing behaviour as intended and correct?

Or is the following fix correct?

Some extra "created new head" pops up with this fix, but it seems to me like
they could be considered correct. The old branch head has been superseeded by
changes on the other branch, and when the changes on the other branch is merged
back to the branch it will introduce a new head not directly related to the
previous branch head.

(I guess the intention with existing behaviour could be to ensure that the
changesets on the branch are directly connected and that no new heads pops up
on merges.)

  $ branchcache=.hg/branchheads.cache

  $ hg init t
  $ cd t

  $ hg branches
  $ echo foo > a
  $ hg add a
  $ hg ci -m "initial"
  $ hg branch foo
  marked working directory as branch foo
  $ hg branch
  foo
  $ hg ci -m "add branch name"
  $ hg branch bar
  marked working directory as branch bar
  $ hg ci -m "change branch name"

Branch shadowing:

  $ hg branch default
  abort: a branch of the same name already exists (use 'hg update' to switch to it)
  [255]

  $ hg branch -f default
  marked working directory as branch default

  $ hg ci -m "clear branch name"
  created new head

There should be only one default branch head

  $ hg heads .
  changeset:   3:9d567d0b51f9
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     clear branch name
  

  $ hg co foo
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch
  foo
  $ echo bleah > a
  $ hg ci -m "modify a branch"

  $ hg merge default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg branch
  foo
  $ hg ci -m "merge"

  $ hg log
  changeset:   5:dc140083783b
  branch:      foo
  tag:         tip
  parent:      4:98d14f698afe
  parent:      3:9d567d0b51f9
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     merge
  
  changeset:   4:98d14f698afe
  branch:      foo
  parent:      1:0079f24813e2
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a branch
  
  changeset:   3:9d567d0b51f9
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     clear branch name
  
  changeset:   2:ed2bbf4e0102
  branch:      bar
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change branch name
  
  changeset:   1:0079f24813e2
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add branch name
  
  changeset:   0:db01e8ea3388
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     initial
  
  $ hg branches
  foo                            5:dc140083783b
  default                        3:9d567d0b51f9 (inactive)
  bar                            2:ed2bbf4e0102 (inactive)

  $ hg branches -q
  foo
  default
  bar

Test for invalid branch cache:

  $ hg rollback
  rolling back to revision 4 (undo commit)

  $ cp $branchcache .hg/bc-invalid

  $ hg log -r foo
  changeset:   4:98d14f698afe
  branch:      foo
  tag:         tip
  parent:      1:0079f24813e2
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a branch
  
  $ cp .hg/bc-invalid $branchcache

  $ hg --debug log -r foo
  invalidating branch cache (tip differs)
  changeset:   4:98d14f698afeaff8cb612dcf215ce95e639effc3
  branch:      foo
  tag:         tip
  parent:      1:0079f24813e2b73a891577c243684c5066347bc8
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    4:d01b250baaa05909152f7ae07d7a649deea0df9a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       a
  extra:       branch=foo
  description:
  modify a branch
  
  
  $ rm $branchcache
  $ echo corrupted > $branchcache

  $ hg log -qr foo
  4:98d14f698afe

  $ cat $branchcache
  98d14f698afeaff8cb612dcf215ce95e639effc3 4
  9d567d0b51f9e2068b054e1948e1a927f99b5874 default
  98d14f698afeaff8cb612dcf215ce95e639effc3 foo
  ed2bbf4e01029020711be82ca905283e883f0e11 bar

Push should update the branch cache:

  $ hg init ../target

Pushing just rev 0:

  $ hg push -qr 0 ../target

  $ cat ../target/$branchcache
  db01e8ea3388fd3c7c94e1436ea2bd6a53d581c5 0
  db01e8ea3388fd3c7c94e1436ea2bd6a53d581c5 default

Pushing everything:

  $ hg push -qf ../target

  $ cat ../target/$branchcache
  98d14f698afeaff8cb612dcf215ce95e639effc3 4
  9d567d0b51f9e2068b054e1948e1a927f99b5874 default
  98d14f698afeaff8cb612dcf215ce95e639effc3 foo
  ed2bbf4e01029020711be82ca905283e883f0e11 bar

Update with no arguments: tipmost revision of the current branch:

  $ hg up -q -C 0
  $ hg up -q
  $ hg id
  9d567d0b51f9

  $ hg up -q 1
  $ hg up -q
  $ hg id
  98d14f698afe (foo) tip

  $ hg branch foobar
  marked working directory as branch foobar

  $ hg up
  abort: branch foobar not found
  [255]

Fastforward merge:

  $ hg branch ff
  marked working directory as branch ff

  $ echo ff > ff
  $ hg ci -Am'fast forward'
  adding ff

  $ hg up foo
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg merge ff
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg branch
  foo
  $ hg commit -m'Merge ff into foo'
  created new head
  $ hg parents
  changeset:   6:6af8030670c9
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Merge ff into foo
  
  $ hg manifest
  a
  ff


Test merging, add 3 default heads and one test head:

  $ cd ..
  $ hg init merges
  $ cd merges
  $ echo a > a
  $ hg ci -Ama
  adding a

  $ echo b > b
  $ hg ci -Amb
  adding b

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo c > c
  $ hg ci -Amc
  adding c
  created new head

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo d > d
  $ hg ci -Amd
  adding d
  created new head

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg branch test
  marked working directory as branch test
  $ echo e >> e
  $ hg ci -Ame
  adding e

  $ hg log
  changeset:   4:3a1e01ed1df4
  branch:      test
  tag:         tip
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  changeset:   3:980f7dc84c29
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     d
  
  changeset:   2:d36c0562f908
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:d2ae7f538514
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
Implicit merge with test branch as parent:

  $ hg merge
  abort: branch 'test' has one head - please merge with an explicit rev
  (run 'hg heads' to see all heads)
  [255]
  $ hg up -C default
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

Implicit merge with default branch as parent:

  $ hg merge
  abort: branch 'default' has 3 heads - please merge with an explicit rev
  (run 'hg heads .' to see heads)
  [255]

3 branch heads, explicit merge required:

  $ hg merge 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m merge

2 branch heads, implicit merge works:

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)