[PATCH 2/2] fix cherry-pick/revert status after commit

[Phillip Wood <phillip.wood123@gmail.com>]

From: Phillip Wood <phillip.wood@dunelm.org.uk>

If the user commits a conflict resolution using 'git commit' during a
sequence of picks then 'git status' missed the fact that a
cherry-pick/revert is still in progress.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---

Notes:
    I'm not user about printing the oid of the commit that was just picked,
    maybe we should just say that a cherry-pick/revert is in progress. That
    will mean auditing all the consumers of wt_status_get_state() to ensure
    they can cope with a null oid.

sequencer.c            | 37 +++++++++++++++++++++++++++++++++++++
 sequencer.h            |  2 ++
 t/t7512-status-help.sh | 19 +++++++++++++++++++
 wt-status.c            | 12 +++++++++++-
 4 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/sequencer.c b/sequencer.c
index 028699209f..5595cc786f 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -2142,6 +2142,43 @@ static int parse_insn_line(struct repository *r, struct todo_item *item,
 	return !item->commit;
 }
 
+int sequencer_get_last_command(struct repository *r, enum replay_action *action,
+			       struct object_id *oid)
+{
+	struct todo_item item;
+	char *eol;
+	const char *todo_file;
+	struct strbuf buf = STRBUF_INIT;
+	int ret = -1;
+
+	todo_file = git_path_todo_file();
+	if (strbuf_read_file(&buf, todo_file, 0) < 0) {
+		if (errno == ENOENT)
+			return -1;
+		else
+			return error_errno("unable to open '%s'", todo_file);
+	}
+	eol = strchrnul(buf.buf, '\n');
+	if (buf.buf != eol && eol[-1] == '\r')
+		eol--; /* strip Carriage Return */
+	if (parse_insn_line(r, &item, buf.buf, eol))
+		goto fail;
+	if (item.command == TODO_PICK)
+		*action = REPLAY_PICK;
+	else if (item.command == TODO_REVERT)
+		*action = REPLAY_REVERT;
+	else
+		goto fail;
+
+	oidcpy(oid, &item.commit->object.oid);
+	ret = 0;
+
+ fail:
+	strbuf_release(&buf);
+
+	return ret;
+}
+
 static int parse_insn_buffer(struct repository *r, char *buf,
 			     struct todo_list *todo_list)
 {
diff --git a/sequencer.h b/sequencer.h
index 43548295a1..815c68c4a3 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -145,3 +145,5 @@ void parse_strategy_opts(struct replay_opts *opts, char *raw_opts);
 int write_basic_state(struct replay_opts *opts, const char *head_name,
 		      const char *onto, const char *orig_head);
 void sequencer_post_commit_cleanup(void);
+int sequencer_get_last_command(struct repository* r, enum replay_action *action,
+			       struct object_id *oid);
diff --git a/t/t7512-status-help.sh b/t/t7512-status-help.sh
index 458608cc1e..71d28a50f7 100755
--- a/t/t7512-status-help.sh
+++ b/t/t7512-status-help.sh
@@ -780,6 +780,25 @@ EOF
 	test_i18ncmp 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" &&
+	test_must_fail git cherry-pick cherry_branch_second one_cherry &&
+	TO_CHERRY_PICK=$(git rev-parse --short CHERRY_PICK_HEAD) &&
+	echo end >main.txt &&
+	git commit -a &&
+	cat >expected <<EOF &&
+On branch cherry_branch
+You are currently cherry-picking commit $TO_CHERRY_PICK.
+  (all conflicts fixed: run "git cherry-pick --continue")
+  (use "git cherry-pick --abort" to cancel the cherry-pick operation)
+
+nothing to commit (use -u to show untracked files)
+EOF
+	git status --untracked-files=no >actual &&
+	test_i18ncmp expected actual
+'
+
 test_expect_success 'status showing detached at and from a tag' '
 	test_commit atag tagging &&
 	git checkout atag &&
diff --git a/wt-status.c b/wt-status.c
index 1f564b12d2..355e4cd03d 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -17,6 +17,7 @@
 #include "utf8.h"
 #include "worktree.h"
 #include "lockfile.h"
+#include "sequencer.h"
 
 static const char cut_line[] =
 "------------------------ >8 ------------------------\n";
@@ -1563,6 +1564,7 @@ void wt_status_get_state(struct repository *r,
 {
 	struct stat st;
 	struct object_id oid;
+	enum replay_action action;
 
 	if (!stat(git_path_merge_head(r), &st)) {
 		wt_status_check_rebase(NULL, state);
@@ -1580,7 +1582,15 @@ void wt_status_get_state(struct repository *r,
 		state->revert_in_progress = 1;
 		oidcpy(&state->revert_head_oid, &oid);
 	}
-
+	if (!sequencer_get_last_command(r, &action, &oid)) {
+		if (action == REPLAY_PICK) {
+			state->cherry_pick_in_progress = 1;
+			oidcpy(&state->cherry_pick_head_oid, &oid);
+		} else {
+			state->revert_in_progress = 1;
+			oidcpy(&state->revert_head_oid, &oid);
+		}
+	}
 	if (get_detached_from)
 		wt_status_get_detached_from(r, state);
 }
-- 
2.21.0