fix cherry-pick/revert status when doing multiple commits

Commit Message

Jacob Keller June 21, 2023, 10:07 p.m. UTC

From: Jacob Keller <[e-mail]>

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 <[e-mail]>
---
 wt-status.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Phillip Wood June 27, 2023, 1:13 p.m. UTC | #1

Hi Jacob

On 21/06/2023 23:07, Jacob Keller wrote:
> From: Jacob Keller <[e-mail]>
> 
> 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.

Thanks for the detailed explanation, I agree with your diagnosis and 
fix. The test case you mention seems to be missing though. I've left one 
small comment below

> Signed-off-by: Jacob Keller <[e-mail]>
> ---
>   wt-status.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/wt-status.c b/wt-status.c
> index 068b76ef6d96..1e2daca73024 100644
> --- a/wt-status.c
> +++ b/wt-status.c
> @@ -1790,10 +1790,11 @@ 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 {
> +		}
> +		if (action == REPLAY_REVERT && !state->revert_in_progress) {

I think this would be clearer as

-		} else {
+		} else if ((action == REPLAY_PICK && !state->cherry_pick_in_progress) {

not worth a re-roll on its own, but I think it is worth considering when 
you re-roll with the missing test.

Thanks for working on this,

Phillip

>   			state->revert_in_progress = 1;
>   			oidcpy(&state->revert_head_oid, null_oid());
>   		}

Patch

diff --git a/wt-status.c b/wt-status.c
index 068b76ef6d96..1e2daca73024 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1790,10 +1790,11 @@  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 {
+		}
+		if (action == REPLAY_REVERT && !state->revert_in_progress) {
 			state->revert_in_progress = 1;
 			oidcpy(&state->revert_head_oid, null_oid());
 		}