import: use dirstateguard instead of dirstate.invalidate
Before this patch, "commands.import()" uses "dirstate.invalidate()" as
a kind of "restore .hg/dirstate to the original status" during a failure.
But it just discards changes in memory, and doesn't actually restore
".hg/dirstate". Then, it can't work as expected, if "dirstate.write()"
is executed while processing.
This patch uses "dirstateguard" instead of "dirstate.invalidate()" to
restore ".hg/dirstate" at failure even if "dirstate.write()" is
executed before failure.
This patch also removes "beginparentchage()" and "endparentchange()",
because "dirstateguard" makes them useless, too.
This is a part of preparations to fix the issue that the recent (in
memory) dirstate isn't visible to external process (e.g. "precommit"
hook).
$ 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: not a linear update
(merge or update --check to force update)
[255]
$ rm b
$ hg update -c
abort: uncommitted changes
[255]
$ hg revert b
$ hg update -c
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mv a c
Should abort:
$ hg update 1
abort: uncommitted changes
(commit or update --clean to discard changes)
[255]
$ mv c a
Should succeed:
$ hg update 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved