v2fix cherry-pick/revert status when doing multiple commits

> From: Jacob Keller <jacob.keller@gmail.com>
> 
> The status report for an in-progress cherry-pick does not show the
> current commit if the cherry-pick happens as part of a series of
> multiple commits:
> 
>   $ git cherry-pick <commit1> <commit2>
>   < one of the cherry-picks fails to merge clean >
>   Cherry-pick currently in progress.
>    (run "git cherry-pick --continue" to continue)
>    (use "git cherry-pick --skip" to skip this patch)
>    (use "git cherry-pick --abort" to cancel the cherry-pick operation)
> 
>   $ git status
>   On branch <branch>
>   Your branch is ahead of '<upstream>' by 1 commit.
>     (use "git push" to publish your local commits)
> 
>   Cherry-pick currently in progress.
>     (run "git cherry-pick --continue" to continue)
>     (use "git cherry-pick --skip" to skip this patch)
>     (use "git cherry-pick --abort" to cancel the cherry-pick operation)
> 
> The show_cherry_pick_in_progress() function prints "Cherry-pick
> currently in progress". That function does have a more verbose print
> based on whether the cherry_pick_head_oid is null or not. If it is not
> null, then a more helpful message including which commit is actually
> being picked is displayed.
> 
> The introduction of the "Cherry-pick currently in progress" message
> comes from 4a72486de97b ("fix cherry-pick/revert status after commit",
> 2019-04-17). This commit modified wt_status_get_state() in order to
> detect that a cherry-pick was in progress even if the user has used `git
> commit` in the middle of the sequence.
> 
> The check used to detect this is the call to sequencer_get_last_command.
> If the sequencer indicates that the lass command was a REPLAY_PICK, then
> the state->cherry_pick_in_progress is set to 1 and the
> cherry_pick_head_oid is initialized to the null_oid. Similar behavior is
> done for the case of REPLAY_REVERT.
> 
> It happens that this call of sequencer_get_last_command will always
> report the action even if the user hasn't interrupted anything. Thus,
> during a range of cherry-picks or reverts, the cherry_pick_head_oid and
> revert_head_oid will always be overwritten and initialized to the null
> oid.
> 
> This results in status always displaying the terse message which does
> not include commit information.
> 
> Fix this by adding an additional check so that we do not re-initialize
> the cherry_pick_head_oid or revert_head_oid if we have already set the
> cherry_pick_in_progress or revert_in_progress bits. This ensures that
> git status will display the more helpful information when its available.
> Add a test case covering this behavior.
> 
> Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
> ---
> 
> Changes since v1:
> * add the missing test case that I had locally but forgot to squash in
> * use else if as suggested by Phillip
> 
>   t/t7512-status-help.sh | 22 ++++++++++++++++++++++
>   wt-status.c            |  4 ++--
>   2 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/t/t7512-status-help.sh b/t/t7512-status-help.sh
> index 2f16d5787edf..c2ab8a444a83 100755
> --- a/t/t7512-status-help.sh
> +++ b/t/t7512-status-help.sh
> @@ -774,6 +774,28 @@ EOF
>   	test_cmp expected actual
>   '
>   
> +test_expect_success 'status when cherry-picking multiple commits' '
> +	git reset --hard cherry_branch &&
> +	test_when_finished "git cherry-pick --abort" &&
> +	test_must_fail git cherry-pick cherry_branch_second one_cherry &&
> +	TO_CHERRY_PICK=$(git rev-parse --short CHERRY_PICK_HEAD) &&
> +	cat >expected <<EOF &&
> +On branch cherry_branch
> +You are currently cherry-picking commit $TO_CHERRY_PICK.
> +  (fix conflicts and run "git cherry-pick --continue")
> +  (use "git cherry-pick --skip" to skip this patch)
> +  (use "git cherry-pick --abort" to cancel the cherry-pick operation)
> +
> +Unmerged paths:
> +  (use "git add <file>..." to mark resolution)
> +	both modified:   main.txt
> +
> +no changes added to commit (use "git add" and/or "git commit -a")
> +EOF
> +	git status --untracked-files=no >actual &&
> +	test_cmp expected actual
> +'
> +
>   test_expect_success 'status when cherry-picking after committing conflict resolution' '
>   	git reset --hard cherry_branch &&
>   	test_when_finished "git cherry-pick --abort" &&
> diff --git a/wt-status.c b/wt-status.c
> index 068b76ef6d96..8d23ff8ced23 100644
> --- a/wt-status.c
> +++ b/wt-status.c
> @@ -1790,10 +1790,10 @@ void wt_status_get_state(struct repository *r,
>   		oidcpy(&state->revert_head_oid, &oid);
>   	}
>   	if (!sequencer_get_last_command(r, &action)) {
> -		if (action == REPLAY_PICK) {
> +		if (action == REPLAY_PICK && !state->cherry_pick_in_progress) {
>   			state->cherry_pick_in_progress = 1;
>   			oidcpy(&state->cherry_pick_head_oid, null_oid());
> -		} else {
> +		} else if (action == REPLAY_REVERT && !state->revert_in_progress) {
>   			state->revert_in_progress = 1;
>   			oidcpy(&state->revert_head_oid, null_oid());
>   		}

> Hi Jacob
>
> This version looks good to me
>
> Thanks for re-rolling
>
> Phillip