tests/test-merge9.t

scmutil: consistently return subrepos relative to ctx1 from itersubrepos()

Previously, if a subrepo was added in ctx2 and then compared to another without
it (ctx1), the subrepo for ctx2 was returned amongst all of the ctx1 based
subrepos, since no subrepo exists in ctx1 to replace it in the 'subpaths' dict.
The two callers of this, basectx.status() and cmdutil.diffordiffstat(), both
compare the yielded subrepo against ctx2, and thus saw no changes when ctx2's
subrepo was returned.  The tests here previously didn't mention 's/a' for the
'p1()' case.

This appears to have been a known issue, because some diffordiffstat() comments
mention that the subpath disappeared, and "the best we can do is ignore it".  I
originally ran into the issue with some custom convert code to flatten a tree of
subrepos causing hg.putcommit() to abort, but this new behavior seems like the
correct status and diff behavior regardless.  (The abort in convert isn't
something users will see, because convert doesn't currently support subrepos in
the official repo.)

test that we don't interrupt the merge session if
a file-level merge failed

  $ hg init repo
  $ cd repo

  $ echo foo > foo
  $ echo a > bar
  $ hg ci -Am 'add foo'
  adding bar
  adding foo

  $ hg mv foo baz
  $ echo b >> bar
  $ echo quux > quux1
  $ hg ci -Am 'mv foo baz'
  adding quux1

  $ hg up -qC 0
  $ echo >> foo
  $ echo c >> bar
  $ echo quux > quux2
  $ hg ci -Am 'change foo'
  adding quux2
  created new head

test with the rename on the remote side
  $ HGMERGE=false hg merge
  merging bar
  merging bar failed!
  merging foo and baz to baz
  1 files updated, 1 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ hg resolve -l
  U bar
  R baz

test with the rename on the local side
  $ hg up -C 1
  3 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ HGMERGE=false hg merge
  merging bar
  merging bar failed!
  merging baz and foo to baz
  1 files updated, 1 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

show unresolved
  $ hg resolve -l
  U bar
  R baz

unmark baz
  $ hg resolve -u baz

show
  $ hg resolve -l
  U bar
  U baz
  $ hg st
  M bar
  M baz
  M quux2
  ? bar.orig

re-resolve baz
  $ hg resolve baz
  merging baz and foo to baz

after resolve
  $ hg resolve -l
  U bar
  R baz

resolve all warning
  $ hg resolve
  abort: no files or directories specified
  (use --all to remerge all files)
  [255]

resolve all
  $ hg resolve -a
  merging bar
  warning: conflicts during merge.
  merging bar incomplete! (edit conflicts, then use 'hg resolve --mark')
  [1]

after
  $ hg resolve -l
  U bar
  R baz

  $ cd ..