dirstate: rename forget to drop
It has substantially different semantics from forget at the command
layer, so change it to avoid confusion.
We can't simply combine it with remove because we need to explicitly
drop non-added files in some cases like commit.
$ 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 use --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