templatekw: add p1rev, p1node, p2rev, p2node keywords
The {parents} template is cumbersome for some uses, as it does not show
anything if there's only one "natural" parent and you can't use it to get the
full 40 digit node hashes for parents unless you rely on the behavior of
the --debug flag.
Introduce four new template keywords: {p1rev}, {p2rev}, {p1node} and
{p2node}. The "node" flavors of these always show full 40 digit hashes,
but users can get the short version with a filter construction like
'{p1node|short}'.
$ hg init
$ echo This is file a1 > a
$ echo This is file b1 > b
$ hg add a b
$ hg commit -m "commit #0"
$ echo This is file b22 > b
$ hg commit -m "comment #1"
$ hg update 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ rm b
$ hg commit -A -m "comment #2"
removing b
created new head
$ hg update 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg update
abort: crosses branches (merge branches or update --check to force update)
[255]
$ hg update -c
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mv a c
In theory, we shouldn't need the "-y" below, but it prevents this test
from hanging when "hg update" erroneously prompts the user for "keep
or delete".
Should abort:
$ hg update -y 1
abort: crosses branches (merge branches or use --clean to discard changes)
[255]
$ mv c a
Should succeed:
$ hg update -y 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved