comparison tests/test-shelve.t @ 42050:03f6480bfdda

unshelve: disable unshelve during merge (issue5123)

As stated in the issue5123, unshelve can destroy the second parent of
the context when tried to unshelve with an uncommitted merge. This
patch makes unshelve to abort when called with an uncommitted merge.

See how shelve.mergefiles works. Commit structure looks like this:
```
... -> pctx -> tmpwctx -> shelvectx
                  /
                 /
        second
        merge parent

pctx = parent before merging working context(first merge parent)
tmpwctx = commited working directory after merge(with two parents)
shelvectx = shelved context
```
shelve.mergefiles first updates to pctx then it reverts shelvectx to pctx with:

```
cmdutil.revert(ui, repo, shelvectx, repo.dirstate.parents(),
                       *pathtofiles(repo, files),
                       **{'no_backup': True})
```

Reverting tmpwctx files that were merged from second parent to pctx makes them
added because they are not in pctx.

Changing this revert operation is crucial to restore parents after unshelve.
This is a complicated issue as this is not fixing a regression. Thus, for the
time being, unshelve during an uncommitted merge can be aborted.

(Details taken from http://mercurial.808500.n3.nabble.com/PATCH-V3-shelve-restore-parents-after-unshelve-issue5123-tt4036858.html#a4037408)

Differential Revision: https://phab.mercurial-scm.org/D6169

42049:1711f5813a63

  $ hg bookmarks
   \* foo                       (5|19):703117a2acfb (re)
     test                      (4|13):33f7f61e6c5e (re)

  $ cd ..

42050:03f6480bfdda

  $ hg bookmarks
   \* foo                       (5|19):703117a2acfb (re)
     test                      (4|13):33f7f61e6c5e (re)

  $ cd ..

Abort unshelve while merging (issue5123)
----------------------------------------

  $ hg init issue5123
  $ cd issue5123
  $ echo > a
  $ hg ci -Am a
  adding a
  $ hg co null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo > b
  $ hg ci -Am b
  adding b
  created new head
  $ echo > c
  $ hg add c
  $ hg shelve
  shelved as default
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg co 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
-- successful merge with two parents
  $ hg log -G
  @  changeset:   1:406bf70c274f
     tag:         tip
     parent:      -1:000000000000
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     b
  
  @  changeset:   0:ada8c9eb8252
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  
-- trying to pull in the shelve bits
-- unshelve should abort otherwise, it'll eat my second parent.
  $ hg unshelve
  abort: cannot unshelve while merging
  [255]

  $ cd ..