% no working directory
adding a
adding b
adding c
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
adding c
created new head
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
% hg parents
changeset:   3:02d851b7e549
user:        test
date:        Thu Jan 01 00:00:03 1970 +0000
summary:     c

% hg parents a
changeset:   1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:01 1970 +0000
summary:     a

% hg parents c, single revision
changeset:   3:02d851b7e549
user:        test
date:        Thu Jan 01 00:00:03 1970 +0000
summary:     c

% hg parents -r 3 c
abort: 'c' not found in manifest!
% hg parents -r 2
changeset:   1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:01 1970 +0000
summary:     a

% hg parents -r 2 a
changeset:   1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:01 1970 +0000
summary:     a

% hg parents -r 2 ../a
abort: ../a not under root
% cd dir; hg parents -r 2 ../a
changeset:   1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:01 1970 +0000
summary:     a

% hg parents -r 2 path:a
changeset:   1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:01 1970 +0000
summary:     a

% hg parents -r 2 glob:a
abort: can only specify an explicit file name
% merge working dir with 2 parents, hg parents c
merging c
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
changeset:   3:02d851b7e549
user:        test
date:        Thu Jan 01 00:00:03 1970 +0000
summary:     c

changeset:   4:48cee28d4b4e
tag:         tip
parent:      1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:04 1970 +0000
summary:     c2

% merge working dir with 1 parent, hg parents
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
changeset:   2:6cfac479f009
user:        test
date:        Thu Jan 01 00:00:02 1970 +0000
summary:     b

changeset:   4:48cee28d4b4e
tag:         tip
parent:      1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:04 1970 +0000
summary:     c2

% merge working dir with 1 parent, hg parents c
changeset:   4:48cee28d4b4e
tag:         tip
parent:      1:d786049f033a
user:        test
date:        Thu Jan 01 00:00:04 1970 +0000
summary:     c2