tests/test-merge-local.out

localrepo.commit: grab locks before getting the list of files to commit

Somebody may change the dirstate after we've determined the parents of
the working dir and run repo.status, but before we called wlock().

This should also fix issue997, where backout would change a file without
changing its size and then call repo.commit without passing the list of
files. If this happened in less than one second, we wouldn't detect any
file changes - the in-memory dirstate still has the cached stat data for
that file. Grabbing the wlock early causes the dirstate to be
invalidated and we end up reading the dirstate file again, which has
that file marked for lookup (size == -1).

A better fix would be for backout to give repo.commit the exact list of
files, but that'll require some changes to the revert operation.

A significant user-visible change is that the precommit hook is always
run with both locks grabbed - previously, hg commit would run it before
grabbing any locks, but hg import would run it after grabbing locks.

# revision 0
adding copy
adding move
adding remove
adding unchanged
adding zzz1_merge_ok
adding zzz2_merge_bad
# revision 1
# local changes to revision 0
4 files updated, 0 files merged, 3 files removed, 0 files unresolved
--- a/zzz1_merge_ok
+++ b/zzz1_merge_ok
+new last line
--- a/zzz2_merge_bad
+++ b/zzz2_merge_bad
+another last line
M zzz1_merge_ok
M zzz2_merge_bad
# local merge with bad merge tool
merging zzz1_merge_ok
merging zzz2_merge_bad
merging zzz2_merge_bad failed!
3 files updated, 1 files merged, 2 files removed, 1 files unresolved
There are unresolved merges with locally modified files.
You can finish the partial merge using:
  hg update 0
  hg update 1
2 files updated, 0 files merged, 3 files removed, 0 files unresolved
--- a/zzz1_merge_ok
+++ b/zzz1_merge_ok
+new first line
+new last line
--- a/zzz2_merge_bad
+++ b/zzz2_merge_bad
+another last line
M zzz1_merge_ok
M zzz2_merge_bad
? zzz2_merge_bad.orig
# local merge with conflicts
merging zzz1_merge_ok
merging zzz2_merge_bad
warning: conflicts during merge.
merging zzz2_merge_bad failed!
3 files updated, 1 files merged, 2 files removed, 1 files unresolved
There are unresolved merges with locally modified files.
You can finish the partial merge using:
  hg update 0
  hg update 1
2 files updated, 0 files merged, 3 files removed, 0 files unresolved
--- a/zzz1_merge_ok
+++ b/zzz1_merge_ok
+new first line
+new last line
--- a/zzz2_merge_bad
+++ b/zzz2_merge_bad
+another last line
+=======
+new last line
M zzz1_merge_ok
M zzz2_merge_bad
? zzz2_merge_bad.orig
# local merge without conflicts
merging zzz1_merge_ok
4 files updated, 1 files merged, 2 files removed, 0 files unresolved
--- a/zzz1_merge_ok
+++ b/zzz1_merge_ok
+new last line
M zzz1_merge_ok
? zzz2_merge_bad.orig